Dreaded freeze with grey "restart" box

Question

Hi all,
It's been a while since I last had an issue. Hopefully I can resolve this with your help.
I've got this iBook G4 (1.33 GHz PPC; 1 GB RAM; HD not full) that's been solid and steady for a couple years, and recently these last 2 days, I've gotten the dreaded freeze acompanied by the grey screen and box in several languages telling me to restart the computer several times. There's no pattern to when it might freeze, but it's happened about 7 times yesterday and a handful today. But never before that.
I've done some searching thru the discussions, and found some related issues, but I'm not totally sure they are the same as mine.
Either it's a hardware issue (i.e., new loose chips) or I'm having some kernel panic issues. I don't have the original install disks here at the moment, or I'd run the hardware check. I will do that tonight or tomorrow.
I've found these:
shimming: http://www.coreyarnold.org/ibook/
kenel panic: http://www.thexlab.com/faqs/kernelpanics.html
Does anyone else have suggestions?
Thanks in advance,
kzrt
Oh - here is my panic log, in case it makes sense to someone out there and can help:
panic.log:
Description: Panic (system crashes) log
Size: 3.66 KB
Last Modified: 11/27/07 3:12 PM
Location: /Library/Logs/panic.log
Recent Contents: Tue Nov 27 14:26:26 2007
panic(cpu 0 caller 0x000A8A00): Uncorrectable machine check: pc = 000000000072B9D8, msr = 0000000000149030, dsisr = 40000000, dar = 000000002193C040
AsyncSrc = 0000000000000000, CoreFIR = 0000000000000000
L2FIR = 0000000000000000, BusFir = 0000000000000000
Latest stack backtrace for cpu 0:
Backtrace:
0x000952D8 0x000957F0 0x00026898 0x000A8A00 0x000A7C90 0x000AB980
Proceeding back via exception chain:
Exception state (sv=0x3A9DCC80)
PC=0x0072B9D8; MSR=0x00149030; DAR=0x2193C040; DSISR=0x40000000; LR=0x0072D6F4; R1=0x17A73CC0; XCP=0x00000008 (0x200 - Machine check)
Backtrace:
0x01E26B00 0x0072D6F4 0x00742094 0x002D130C 0x002D01D4 0x000A9514
Kernel loadable modules in backtrace (with dependencies):
com.apple.iokit.AppleAirPort2(405.1)@0x703000
dependency: com.apple.iokit.IONetworkingFamily(1.5.0)@0x630000
dependency: com.apple.iokit.IOPCIFamily(1.7)@0x469000
Exception state (sv=0x31FEE500)
PC=0x00000000; MSR=0x0000D030; DAR=0x00000000; DSISR=0x00000000; LR=0x00000000; R1=0x00000000; XCP=0x00000000 (Unknown)
Kernel version:
Darwin Kernel Version 8.10.0: Wed May 23 16:50:59 PDT 2007; root:xnu-792.21.3~1/RELEASE_PPC
Tue Nov 27 15:02:02 2007
panic(cpu 0 caller 0x000A8A00): Uncorrectable machine check: pc = 000000000072D52C, msr = 0000000000149030, dsisr = 42000000, dar = 00000000000FE014
AsyncSrc = 0000000000000000, CoreFIR = 0000000000000000
L2FIR = 0000000000000000, BusFir = 0000000000000000
Latest stack backtrace for cpu 0:
Backtrace:
0x000952D8 0x000957F0 0x00026898 0x000A8A00 0x000A7C90 0x000AB980
Proceeding back via exception chain:
Exception state (sv=0x3A7AE280)
PC=0x0072D52C; MSR=0x00149030; DAR=0x000FE014; DSISR=0x42000000; LR=0x00742078; R1=0x17743D30; XCP=0x00000008 (0x200 - Machine check)
Backtrace:
0x00000000 0x00742078 0x002D130C 0x002D01D4 0x000A9514
Kernel loadable modules in backtrace (with dependencies):
com.apple.iokit.AppleAirPort2(405.1)@0x703000
dependency: com.apple.iokit.IONetworkingFamily(1.5.0)@0x630000
dependency: com.apple.iokit.IOPCIFamily(1.7)@0x469000
Exception state (sv=0x31EE2000)
PC=0x00000000; MSR=0x0000D030; DAR=0x00000000; DSISR=0x00000000; LR=0x00000000; R1=0x00000000; XCP=0x00000000 (Unknown)
Kernel version:
Darwin Kernel Version 8.10.0: Wed May 23 16:50:59 PDT 2007; root:xnu-792.21.3~1/RELEASE_PPC
Tue Nov 27 15:12:54 2007
panic(cpu 0 caller 0x000A8A00): Uncorrectable machine check: pc = 000000000072D52C, msr = 0000000000149030, dsisr = 42000000, dar = 0000000005E08000
AsyncSrc = 0000000000000000, CoreFIR = 0000000000000000
L2FIR = 0000000000000000, BusFir = 0000000000000000
Latest stack backtrace for cpu 0:
Backtrace:
0x000952D8 0x000957F0 0x00026898 0x000A8A00 0x000A7C90 0x000AB980
Proceeding back via exception chain:
Exception state (sv=0x31F71000)
PC=0x0072D52C; MSR=0x00149030; DAR=0x05E08000; DSISR=0x42000000; LR=0x00742078; R1=0x178C3D30; XCP=0x00000008 (0x200 - Machine check)
Backtrace:
0x0027CDD4 0x00742078 0x002D130C 0x002D01D4 0x000A9514
Kernel loadable modules in backtrace (with dependencies):
com.apple.iokit.AppleAirPort2(405.1)@0x703000
dependency: com.apple.iokit.IONetworkingFamily(1.5.0)@0x630000
dependency: com.apple.iokit.IOPCIFamily(1.7)@0x469000
Exception state (sv=0x31F18C80)
PC=0x00000000; MSR=0x0000D030; DAR=0x00000000; DSISR=0x00000000; LR=0x00000000; R1=0x00000000; XCP=0x00000000 (Unknown)
Kernel version:
Darwin Kernel Version 8.10.0: Wed May 23 16:50:59 PDT 2007; root:xnu-792.21.3~1/RELEASE_PPC

Answer 1

I was reading in bed tonight I had the laptop on my, well, lap, and it wasn't tilted any more than usual. I got a grey screen with all the languages saying SHUT DOWN NOW. I did so. But on bootup, I get this:
Big huge fan noise
Black screen
Dies
Sometimes it actually gives me the initial startup screen with the dial, but then the display gets lines all through it. Then it goes black. I got it once to the point where it was starting to show desktop, but it frizzled to black again. It hasn't given me desktop since, and it doesn't matter if the Airport's plugged in or not. Now it's giving me a backlit screen, but nothing on it; it's very pretty but certainly isn't what I want.
For the last few months, I've been having issues where the display would just suddenly DIE. It'd go black, and if I closed the laptop and let it go to sleep and reopened it, it'd come back just fine. Is that related to the current issue?
In short, would this shim thing be what's wrong? If so, and since it does seem to be a widespread issue, does Apple know about it? (And if it's not something they're taking responsibility for, what kind of prices am I looking at to fix it? My AppleCare lapsed a few months back.)
Please help! This thing's my baby. The only consolation I have now is that it's probably not my hard drive, so at least I haven't lost my latest work.