Kernel panic log - can anyone help me decipher?

Question

I posted this in the Leopard discussion group, but didn't get much response. Can anyone here help me figure out what is causing kernel panics on my iMac G5? Here is the log for the latest one (they all seem to be the same):
Sun Dec 30 20:22:27 2007
Unresolved kernel trap(cpu 0): 0x300 - Data access DAR=0x000000000000000C PC=0x000000000035705C
Latest crash info for cpu 0:
Exception state (sv=0x27084280)
PC=0x0035705C; MSR=0x00009030; DAR=0x0000000C; DSISR=0x42000000; LR=0x003566C0; R1=0x31C1F6F0; XCP=0x0000000C (0x300 - Data access)
Backtrace:
0x00585EAC 0x003566C0 0x00357350 0x00576F60 0x0058E218 0x0057C708
0x00F2FF78 0x00F30224 0x00F3078C 0x00575DC0 0x00570970 0x008AC0DC 0x008AD19C 0x008AD240
0x008A40E0 0x008A4024 0x00355B48 0x00354DAC 0x00354E60 0x000AFE54
Kernel loadable modules in backtrace (with dependencies):
com.apple.iokit.IOUSBMassStorageClass(2.0.0)@0xf2c000->0xf38fff
dependency: com.apple.iokit.IOSCSIArchitectureModelFamily(2.0.0)@0x833000
dependency: com.apple.iokit.IOUSBFamily(3.0.3)@0x56f000
dependency: com.apple.iokit.IOStorageFamily(1.5.2)@0x854000
com.apple.driver.AppleUSBEHCI(3.0.3)@0x89f000->0x8b4fff
dependency: com.apple.iokit.IOPCIFamily(2.4)@0x7a5000
dependency: com.apple.iokit.IOUSBFamily(3.0.3)@0x56f000
com.apple.iokit.IOUSBFamily(3.0.3)@0x56f000->0x5a3fff
Proceeding back via exception chain:
Exception state (sv=0x27084280)
previously dumped as "Latest" state. skipping...
Exception state (sv=0x18b59000)
PC=0x00000000; MSR=0x0000D030; DAR=0x00000000; DSISR=0x00000000; LR=0x00000000; R1=0x00000000; XCP=0x00000000 (Unknown)
BSD process name corresponding to current thread: kernel_task
Mac OS version:
9B18
Kernel version:
Darwin Kernel Version 9.1.0: Wed Oct 31 17:48:21 PDT 2007; root:xnu-1228.0.2~1/RELEASE_PPC
panic(cpu 0 caller 0xFFFF0003): 0x300 - Data access
Latest stack backtrace for cpu 0:
Backtrace:
0x0009AD18 0x0009B6BC 0x00029DC4 0x000AEA90 0x000B22F8
Proceeding back via exception chain:
Exception state (sv=0x27084280)
PC=0x0035705C; MSR=0x00009030; DAR=0x0000000C; DSISR=0x42000000; LR=0x003566C0; R1=0x31C1F6F0; XCP=0x0000000C (0x300 - Data access)
Backtrace:
0x00585EAC 0x003566C0 0x00357350 0x00576F60 0x0058E218 0x0057C708
0x00F2FF78 0x00F30224 0x00F3078C 0x00575DC0 0x00570970 0x008AC0DC 0x008AD19C 0x008AD240
0x008A40E0 0x008A4024 0x00355B48 0x00354DAC 0x00354E60 0x000AFE54
Kernel loadable modules i`
This is what I've tried so far:
Ran hardware test: no problems reported
Ran memory test using Rember: 10 loops, no problems reported
Repaired disk permissions: two were repaired
I just replaced my hard drive and installed Leopard. The hard drive seems to be functioning perfectly, so I'm suspecting it's related to Leopard. I never had a kernel panic until the upgrade. I'm considering going back to Tiger. Thoughts?
Thanks for any help with this.

Answer 1

I upgraded 3 days ago to leopard and have had 5 or six kernel panics. I had the machine running panther for years and never had one before. All similar to what has been described in this thread. I have not been able to get through a time machine back-up all the way yet. I am afraid to leave the machine with time machine active now because the panic mode I get into usually puts the fan on full blast- Can't be good to run for hours like that. I am backing up a lot of files so I wonder if the size of the initial backup is causing the problem. I have gotten through about 150 GB worth with time machine before the crashes set in. If I make any progress I'll post.