IMac i7 restarts randomly. Any idea on what is going on? Error report is as follows:

Question

Interval Since Last Panic Report:  270898 sec
Panics Since Last Report:          2
Anonymous UUID:                    5B88E2FD-1E0B-4DBF-8DC0-1FD609ACEAFA
Wed Jul 24 10:37:55 2013
panic(cpu 4 caller 0xffffff80024b7b95): Kernel trap at 0xffffff800281c924, type 14=page fault, registers:
CR0: 0x0000000080010033, CR2: 0x0000000000000128, CR3: 0x00000000275b101f, CR4: 0x00000000000606e0
RAX: 0x0000000000000128, RBX: 0xffffff8025a26808, RCX: 0xffffff8027ac5408, RDX: 0x00000000000000e0
RSP: 0xffffff81d2eab7e8, RBP: 0xffffff81d2eab820, RSI: 0x0000000000000128, RDI: 0x00000000ffffffff
R8:  0x0000000000004000, R9:  0x0000000000000fff, R10: 0xffffff81d2eab4e0, R11: 0xffffff803c283220
R12: 0x0000000000000000, R13: 0x0000000000000001, R14: 0xffffff803ae585d0, R15: 0xffffff80323c72e8
RFL: 0x0000000000010282, RIP: 0xffffff800281c924, CS:  0x0000000000000008, SS:  0x0000000000000010
Fault CR2: 0x0000000000000128, Error code: 0x0000000000000002, Fault CPU: 0x4
Backtrace (CPU 4), Frame : Return Address
0xffffff81d2eab480 : 0xffffff800241d5f6
0xffffff81d2eab4f0 : 0xffffff80024b7b95
0xffffff81d2eab6c0 : 0xffffff80024ce4ad
0xffffff81d2eab6e0 : 0xffffff800281c924
0xffffff81d2eab820 : 0xffffff800251345c
0xffffff81d2eab850 : 0xffffff80024f19ec
0xffffff81d2eab8a0 : 0xffffff80024f0fe1
0xffffff81d2eab8e0 : 0xffffff80024f14da
0xffffff81d2eab960 : 0xffffff80024f9f68
0xffffff81d2eab9b0 : 0xffffff80024f2f02
0xffffff81d2eabcc0 : 0xffffff800276e4af
0xffffff81d2eabd20 : 0xffffff800276e6ab
0xffffff81d2eabe00 : 0xffffff80024f2882
0xffffff81d2eabe90 : 0xffffff800276a8bd
0xffffff81d2eabf50 : 0xffffff80027e17da
0xffffff81d2eabfb0 : 0xffffff80024cecf3
BSD process name corresponding to current thread: KernelEventAgent
Mac OS version:
12A269
Kernel version:
Darwin Kernel Version 12.0.0: Sun Jun 24 23:00:16 PDT 2012; root:xnu-2050.7.9~1/RELEASE_X86_64
Kernel UUID: 8D5F8EF3-9D12-384B-8070-EF2A49C45D24
Kernel slide:     0x0000000002200000
Kernel text base: 0xffffff8002400000
System model name: iMac12,2 (Mac-942B59F58194171B)
System uptime in nanoseconds: 128647201481382
last loaded kext at 51013118567983: com.apple.filesystems.msdosfs          1.8 (addr 0xffffff7f84709000, size 65536)
last unloaded kext at 59254997226539: com.apple.filesystems.msdosfs          1.8 (addr 0xffffff7f84709000, size 57344)
loaded kexts:
com.apple.driver.AppleIntelProfile          97
com.apple.filesystems.smbfs          1.8
com.apple.driver.AppleHWSensor          1.9.5d0
com.apple.iokit.IOBluetoothSerialManager          4.0.9f8
com.apple.driver.AudioAUUC          1.60
com.apple.driver.AGPM          100.12.69
com.apple.driver.AppleMikeyHIDDriver          122
com.apple.driver.AppleHDA          2.3.0f2
com.apple.filesystems.autofs          3.0
com.apple.driver.AppleUpstreamUserClient          3.5.10
com.apple.iokit.IOUserEthernet          1.0.0d1
com.apple.kext.AMDFramebuffer          8.0.0
com.apple.driver.AppleMikeyDriver          2.3.0f2
com.apple.driver.AppleSMCLMU          2.0.2d0
com.apple.driver.AppleLPC          1.6.0
com.apple.Dont_Steal_Mac_OS_X          7.0.0
com.apple.AMDRadeonAccelerator          1.0.0
com.apple.iokit.BroadcomBluetoothHCIControllerUSBTransport          4.0.9f8
com.apple.driver.ACPI_SMC_PlatformPlugin          1.0.0
com.apple.driver.ApplePolicyControl          3.2.6
com.apple.driver.AppleSMCPDRC          1.0.0
com.apple.driver.AppleIntelHD3000Graphics          8.0.0
com.apple.driver.AppleIntelSNBGraphicsFB          8.0.0
com.apple.driver.AppleBacklight          170.2.3
com.apple.driver.AppleMCCSControl          1.0.33
com.apple.iokit.SCSITaskUserClient          3.5.1
com.apple.driver.AppleUSBCardReader          3.1.0
com.apple.driver.AppleIRController          320.15
com.apple.driver.XsanFilter          404
com.apple.iokit.IOAHCIBlockStorage          2.2.0
com.apple.AppleFSCompression.AppleFSCompressionTypeDataless          1.0.0d1
com.apple.AppleFSCompression.AppleFSCompressionTypeZlib          1.0.0d1
com.apple.BootCache          34
com.apple.driver.AppleUSBHub          5.1.6
com.apple.driver.AirPort.Atheros40          600.70.23
com.apple.driver.AppleFWOHCI          4.9.5
com.apple.iokit.AppleBCM5701Ethernet          3.2.5b3
com.apple.driver.AppleAHCIPort          2.4.0
com.apple.driver.AppleUSBEHCI          5.1.5
com.apple.driver.AppleEFINVRAM          1.6.1
com.apple.driver.AppleACPIButtons          1.6
com.apple.driver.AppleRTC          1.5
com.apple.driver.AppleHPET          1.7
com.apple.driver.AppleSMBIOS          1.9
com.apple.driver.AppleACPIEC          1.6
com.apple.driver.AppleAPIC          1.6
com.apple.driver.AppleIntelCPUPowerManagementClient          196.0.0
com.apple.nke.applicationfirewall          4.0.39
com.apple.security.quarantine          2
com.apple.driver.AppleIntelCPUPowerManagement          196.0.0
com.apple.driver.AppleProfileTimestampAction          97
com.apple.driver.AppleProfileThreadInfoAction          97
com.apple.driver.AppleProfileRegisterStateAction          97
com.apple.driver.AppleProfileReadCounterAction          97
com.apple.driver.AppleProfileKEventAction          97
com.apple.driver.AppleProfileCallstackAction          97
com.apple.iokit.AppleProfileFamily          97
com.apple.iokit.IOSerialFamily          10.0.6
com.apple.driver.DspFuncLib          2.3.0f2
com.apple.iokit.IOAudioFamily          1.8.9fc9
com.apple.kext.OSvKernDSPLib          1.6
com.apple.kext.triggers          1.0
com.apple.iokit.IOSurface          86.0.2
com.apple.iokit.IOBluetoothFamily          4.0.9f8
com.apple.driver.AppleThunderboltEDMSink          1.1.8
com.apple.driver.AppleThunderboltEDMSource          1.1.8
com.apple.driver.AppleHDAController          2.3.0f2
com.apple.iokit.IOHDAFamily          2.3.0f2
com.apple.iokit.IOAcceleratorFamily          19.0.26
com.apple.iokit.AppleBluetoothHCIControllerUSBTransport          4.0.9f8
com.apple.driver.IOPlatformPluginLegacy          1.0.0
com.apple.driver.IOPlatformPluginFamily          5.2.0d16
com.apple.driver.AppleSMBusPCI          1.0.10d0
com.apple.driver.AppleSMC          3.1.3d11
com.apple.kext.AMD6000Controller          8.0.0
com.apple.kext.AMDSupport          8.0.0
com.apple.iokit.IOFireWireIP          2.2.5
com.apple.driver.AppleGraphicsControl          3.2.6
com.apple.driver.AppleBacklightExpert          1.0.4
com.apple.iokit.IONDRVSupport          2.3.4
com.apple.driver.AppleSMBusController          1.0.10d0
com.apple.iokit.IOGraphicsFamily          2.3.4
com.apple.driver.AppleUSBHIDKeyboard          165.5
com.apple.driver.AppleHIDKeyboard          165.5
com.apple.driver.AppleThunderboltDPOutAdapter          1.8.5
com.apple.driver.AppleThunderboltDPInAdapter          1.8.5
com.apple.driver.AppleThunderboltDPAdapterFamily          1.8.5
com.apple.driver.AppleThunderboltPCIDownAdapter          1.2.5
com.apple.iokit.IOSCSIMultimediaCommandsDevice          3.5.1
com.apple.iokit.IOBDStorageFamily          1.7
com.apple.iokit.IODVDStorageFamily          1.7.1
com.apple.iokit.IOCDStorageFamily          1.7.1
com.apple.iokit.IOSCSIBlockCommandsDevice          3.5.1
com.apple.iokit.IOUSBMassStorageClass          3.5.0
com.apple.iokit.IOAHCISerialATAPI          2.5.0
com.apple.iokit.IOSCSIArchitectureModelFamily          3.5.1
com.apple.iokit.IOUSBHIDDriver          5.0.0
com.apple.driver.AppleUSBMergeNub          5.1.5
com.apple.driver.AppleUSBComposite          5.0.0
com.apple.iokit.IOUSBUserClient          5.0.0
com.apple.driver.AppleThunderboltNHI          1.6.0
com.apple.iokit.IOThunderboltFamily          2.0.3
com.apple.iokit.IO80211Family          500.15
com.apple.iokit.IOFireWireFamily          4.5.5
com.apple.iokit.IOEthernetAVBController          1.0.2b1
com.apple.iokit.IONetworkingFamily          3.0
com.apple.iokit.IOAHCIFamily          2.2.0
com.apple.iokit.IOUSBFamily          5.1.6
com.apple.iokit.IOHIDFamily          1.8.0
com.apple.driver.AppleEFIRuntime          1.6.1
com.apple.iokit.IOSMBusFamily          1.1
com.apple.security.sandbox          220
com.apple.kext.AppleMatch          1.0.0d1
com.apple.security.TMSafetyNet          7
com.apple.driver.DiskImages          344
com.apple.iokit.IOStorageFamily          1.8
com.apple.driver.AppleKeyStore          28.18
com.apple.driver.AppleACPIPlatform          1.6
com.apple.iokit.IOPCIFamily          2.7
com.apple.iokit.IOACPIFamily          1.4
com.apple.kec.corecrypto          1.0
Model: iMac12,2, BootROM IM121.0047.B1F, 4 processors, Intel Core i7, 3.4 GHz, 16 GB, SMC 1.72f2
Graphics: AMD Radeon HD 6970M, AMD Radeon HD 6970M, PCIe, 2048 MB
Memory Module: BANK 0/DIMM0, 4 GB, DDR3, 1333 MHz, 0x0198, 0x393930353432382D3037332E4130304C4620
Memory Module: BANK 1/DIMM0, 4 GB, DDR3, 1333 MHz, 0x0198, 0x393930353432382D3037332E4130304C4620
Memory Module: BANK 0/DIMM1, 4 GB, DDR3, 1333 MHz, 0x80AD, 0x484D54333531533643465238432D48392020
Memory Module: BANK 1/DIMM1, 4 GB, DDR3, 1333 MHz, 0x80AD, 0x484D54333531533643465238432D48392020
AirPort: spairport_wireless_card_type_airport_extreme (0x168C, 0x9A), Atheros 9380: 4.0.70.23-P2P
Bluetooth: Version 4.0.9f8 10405, 2 service, 18 devices, 1 incoming serial ports
Network Service: Ethernet, Ethernet, en0
Serial ATA Device: ST31000528AS, 1 TB
Serial ATA Device: HL-DT-STDVDRW  GA32N
USB Device: hub_device, 0x0424  (SMSC), 0x2514, 0xfa100000 / 3
USB Device: Microsoft Optical Mouse with Tilt Wheel, 0x045e  (Microsoft Corporation), 0x00d1, 0xfa130000 / 5
USB Device: BRCM2046 Hub, 0x0a5c  (Broadcom Corp.), 0x4500, 0xfa110000 / 4
USB Device: Bluetooth USB Host Controller, apple_vendor_id, 0x8215, 0xfa111000 / 6
USB Device: FaceTime HD Camera (Built-in), apple_vendor_id, 0x850b, 0xfa200000 / 2
USB Device: hub_device, 0x0424  (SMSC), 0x2514, 0xfd100000 / 2
USB Device: My Passport 0748, 0x1058  (Western Digital Technologies, Inc.), 0x0748, 0xfd130000 / 6
USB Device: Keyboard Hub, apple_vendor_id, 0x1006, 0xfd140000 / 5
USB Device: Apple Keyboard, apple_vendor_id, 0x024f, 0xfd142000 / 7
USB Device: IR Receiver, apple_vendor_id, 0x8242, 0xfd120000 / 4
USB Device: Internal Memory Card Reader, apple_vendor_id, 0x8403, 0xfd110000 / 3

Answer 1

That panic was not caused by third-party software. If the problem is recurrent, the possibilities are:
A stale or corrupt kernel cache
A damaged OS X installation
A fault in a peripheral device, if any
Corrupt non-volatile memory (NVRAM)
An internal hardware fault (including incompatible memory)
An obscure bug in OS X
You may already have ruled out some of these.
Rule out #1 by booting in safe mode and then rebooting as usual. Note: If FileVault is enabled, or if a firmware password is set, or if the boot volume is a software RAID, you can’t do this. Post for further instructions.
You can rule out #2 and #3 by reinstalling the OS and testing with non-essential peripherals disconnected and aftermarket expansion cards removed, if applicable. Sometimes a clean reinstallation (after erasing the startup volume) may solve a problem that isn't solved by reinstalling in place, without erasing.
Corrupt NVRAM, which rarely causes panics, can be ruled out by resetting it.
If your model has user-replaceable memory, and you've upgraded the memory modules, reinstall the original memory and see whether there's any improvement. Be careful not to touch the gold contacts. Clean them with a mild solvent such as rubbing alcohol. Aftermarket memory must exactly match the technical specifications for your model. Memory that is either slower or faster than specified may be incompatible.
The Apple Hardware Test or Apple Diagnostics, though generally unreliable, will sometimes detect a fault. A negative test can't be depended on. Run the extended version of the test.
In the category of obscure bugs, reports suggest that FileVault may trigger kernel traps under some unknown conditions. Most, though not all, of these reports seem to involve booting from an aftermarket SSD. If those conditions apply to you, try deactivating FileVault.
Connecting more than one display is another reported trigger for OS X bugs.
If your system is not fully up to date, running Software Update might get you a bug fix.
In rare cases, a malformed network packet from a defective router or other network device can cause panics. Such packets could also be sent deliberately by a skillful attacker. This possibility is something to consider if you run a public server that might be the target of such an attack.
If none of the above applies, make a "Genius" appointment at an Apple Store to have the machine tested. You may have to leave it there for several days. There isn't much point in doing this unless you can reproduce the panic, or if you can't, it happens often enough that it's likely to be repeated at the store. Otherwise you may be told that nothing is wrong.
Print the first page of the panic report and bring it with you.
Back up all data on the internal drive(s) before you hand over your computer to anyone. If privacy is a concern, erase the data partition(s) with the option to write zeros* (do this only if you know how to restore, and you have at least  two independent backups.) Don’t erase the recovery partition, if present.
Keeping your confidential data secure during hardware repair
*An SSD doesn't need to be zeroed.