24" iMac repeatedly kernel panics when idle

Question

I have recently been struck by repeated kernel panics on my 24" iMac. Until a few days ago, this happened when I woke it from sleep. Running Applejack showed up a corrupt Kensington MouseWorks pref file and removing that seems to have solved that problem. Now, however, I frequently come back to my iMac to find it kernel panicked. In other words, it panics without me doing anything. A recent example from panic.log is copied below. Is there an obvious fix? I have repaired permissions and checked memory. Thanks!
Sat Dec 2 22:35:55 2006
panic(cpu 1 caller 0x001A3135): Unresolved kernel trap (CPU 1, Type 14=page fault), registers:
CR0: 0x8001003b, CR2: 0x00000024, CR3: 0x01177000, CR4: 0x000006e0
EAX: 0x00000000, EBX: 0x06b8e8b0, ECX: 0x00000000, EDX: 0x040c3a00
CR2: 0x00000024, EBP: 0x2589bf28, ESI: 0x00000001, EDI: 0x040c3a00
EFL: 0x00010246, EIP: 0x00392b8b, CS: 0x00000008, DS: 0x03f90010
Backtrace, Format - Frame : Return Address (4 potential args on stack)
0x2589bd28 : 0x128d1f (0x3c9540 0x2589bd4c 0x131df4 0x0)
0x2589bd68 : 0x1a3135 (0x3cf1f4 0x1 0xe 0x3cea24)
0x2589be78 : 0x19a8d4 (0x2589be90 0x0 0x1 0x3ba1f4)
0x2589bf28 : 0x3945f4 (0x40c3a00 0x10 0x3f768a8 0x37ec3e)
0x2589bf58 : 0x397bf1 (0x3f76880 0x135ec3 0x0 0x3f49144)
0x2589bf88 : 0x397927 (0x3f76800 0x34 0x8000 0xf0b)
0x2589bfc8 : 0x19a74c (0x3f76800 0x0 0x19d0b5 0x4c58144) Backtrace terminated-invalid frame pointer 0x0
Kernel version:
Darwin Kernel Version 8.8.1: Mon Sep 25 19:42:00 PDT 2006; root:xnu-792.13.8.obj~1/RELEASE_I386
iMac 24"   Mac OS X (10.4.8)   2GB Ram, 500GB hard disk, iMac firmware update installed.

Answer 1

"mostly when I woke it from prolonged sleep"
pipas -
First, if your iMac has any third-party RAM, rather than the original Apple RAM, then I'd suggest that is the likely suspect. If so, that may not necessarily be shown in the results of the Apple Hardware Test. Best test of third party RAM is to remove it and replace with only the original Apple RAM, and see what the results of that are.
I don't know how or if Remy resolved his, but based on your above comment, I'd suggest you try the SMC reset, found here:
http://docs.info.apple.com/article.html?artnum=303446
If that doesn't resolve, I'd also try a PRAM reset.
To reset the PRAM:
1. Shut down the computer.
2. Locate the following four keys on the keyboard: Command (Apple logo), option, P, and R. You will need to hold these four keys down simultaneously in step 4.
3. Start up the computer.
4. Press and hold the Command-option-P-R keys. You must press this key combination after the startup chord sounds, but before the gray screen appears.
5. Hold all four keys down until the computer restarts and you hear the startup chord for the second time.
6. Release the keys.
If that wouldn't help, then I suppose you'll have to proceed through the links in my above post.