Kernel Panics & freezing

Question

I just got my imac a few weeks ago and it's been having a lot of kernel panics. Sometimes the computer freezes, but does not show the "you need to restart your computer" dialog. The text in panic.log from the last one is as follows:
Tue Sep 20 22:44:42 2005
panic(cpu 0 caller 0x006F898C): AppleU3ART::mapAddr(0x30404004) not mapped for I/O
Latest stack backtrace for cpu 0:
Backtrace:
0x00095544 0x00095A5C 0x0002683C 0x006F898C 0x002D12DC 0x00464E90 0x0045FAA4 0x0045F770
0x002CF824 0x002E3760 0x0050AC3C 0x002DEED4 0x000ADBA0 0x000AC0C8
Kernel loadable modules in backtrace (with dependencies):
com.apple.driver.AppleMPIC(1.2.3)@0x509000
com.apple.driver.AppleUSBOHCI(2.2.0)@0x45b000
dependency: com.apple.iokit.IOUSBFamily(2.2.0)@0x433000
dependency: com.apple.iokit.IOPCIFamily(1.6)@0x451000
com.apple.driver.AppleMacRiscPCI(3.0)@0x6f3000
dependency: com.apple.iokit.IOPCIFamily(1.6)@0x451000
Proceeding back via exception chain:
Exception state (sv=0x00D0B500)
PC=0x002F7BA4; MSR=0x00009030; DAR=0xEF517000; DSISR=0x42000000; LR=0x002F7B48; R1=0x1767BBD0; XCP=0x00000014 (0x500 - Ext int)
Backtrace:
0x002F7B48 0x002F7D4C 0x002B5430 0x002BA54C 0x0045F494 0x0045F6D8
0x002CD5AC 0x002CC474 0x000A9694
Kernel loadable modules in backtrace (with dependencies):
com.apple.driver.AppleUSBOHCI(2.2.0)@0x45b000
dependency: com.apple.iokit.IOUSBFamily(2.2.0)@0x433000
dependency: com.apple.iokit.IOPCIFamily(1.6)@0x451000
Exception state (sv=0x2785DC80)
PC=0x00000000; MSR=0x0000D030; DAR=0x00000000; DSISR=0x00000000; LR=0x00000000; R1=0x00000000; XCP=0x00000000 (Unknown)
It has happened most often during games, such as Halo, Quake III and Wolfenstien, but occasionally happens completely randomly. Please help if possible, I don't really want to drag it to the apple store if i can avoid it.
Edit: The computer has no other problems besides this: no unfixable sleep issues, no excessive fan noise (mostly), no video problems...
Ran through Apple hardware test, no problems found
Went through thexlab.com's guide except for reformatting the drive and reinstalling

Answer 1

Hi Rod,
Yes, I'm turning off Airport at the iMac G5 computer prior to "Restart" and everything's okay.
Yes, I can turn on Airport after restarting and there's no crash and no problem that I see.
Shut-down and cold power-up works fine with Airport on. It's only "Restart" with Airport on that crashes as the system starts to come back up - i.e. gets to the white screen with the Apple logo then I get the four language/reboot your computer message.
I'm pretty sure that the Base Station has the latest base station software. It's a 2nd generation 802.11 11 Mbps Airport base stastion with the WAN and Ethernet ports)
Two iMac G3's running 10.3.x are also using wireless through this base station and they aren't crashing on Restart or anywhere else. The iMac G5 is running the latest 10.4.x.
I'll try the PRAM reset exercise at power up. I'll also try resetting the SMU (what's that?) by disconnecting from the line power for a few minutes.
If there is a Airport HW issue inside the iMac G5 that would be very bad news. This computer is going to college with my son at the end of this week. I really need to resolve this issue quickly.
Thanks,
Steve