Kernal Panic: Memory, Hard Drive or something else?

Hi there,

A couple of weeks ago I started experiencing random and sudden crashes in various applications (Safari most consistently, but also Mail, Logic Pro, Back Up) as well as strange behavior in iTunes on my 4 1/2 year old G5. I did the usual maintenance stuff (Disk Utility, Disk Warrior) and encountered some weirdness:

When trying to repair permissions after restarting from my Install CD and using Disk Utility, it would get about 1/3 of the way through and then pop up the error:

Disk Utility Internal Error
Disk Utility has lost its connection with the disk management tool and cannot continue. Please quit and relaunch Disk Utility.

I got this error each time I tried repairing permissions, so I tried it with Onyx from the system drive and it claimed to work without any errors.

I tried repairing the drive with Disk Utility, and at the end it said:

The Volume G5 was repaired successfully.
Repair attempted on 2 volumes
1 HFS volume repaired
1 volume COULD NOT be repaired

Weird. My drive is not partitioned, if that makes any difference. So I tried DiskWarrior and it didn't report any problems. But of course I continued to have these random crashes (not freezes, to be specific...the apps would just randomly Quit).

About 4 days ago I had my first kernal panic, with only Safari and Mail open. Tried DU and DW again with the same results. I had another kernal panic the next day, and then two the following day, at basically random times (not at start-up, just during what had been a regular day). I searched these forums for help and ended up getting Drive Genius 2 as well as the great info at The X Lab website.

According to the tests I ran with Drive Genius, there's no problem with my system drive, my second internal drive (used for recording audio to) or my external USB2.0 drive. I then ran another DU test on the main drive and it reported:

"Reserved fields in catalog record have incorrect data" [about 20 times in red]

"Invalid Leaf record count (it should be 124 instead of 245)
The Volume G5 was repaired successfully.
Repair attempted on 2 volumes
1 HFS volume repaired
1 volume could not be repaired"

So I tried the Apple Hardware Test to see if that would offer any clarity. I tried to run it in Loop Mode as suggested by X Lab, but that didn't work, so I ran it twice, with the results that everything passed each time EXCEPT the Memory (although, once the testing stopped at the memory failure, I couldn't figure out how to make it continue on and check the Video RAM, so I don't know if that's in good shape or not).

The Error Code for the first memory failure was:

2MEM/3/4: DIMM3/J14

For the second run-through it was:

2MEM/4/4: DIMM3/J14

I'm assuming that the cause of my woes is my memory, but I worry about DU always reporting that "1 volume could not be repaired." If memory is the culprit, do these error messages imply that it's the memory seated in slots 3 & 4, or how would I determine which ones are bad? In addition to the RAM that came with the G5, I installed 2 512mb cards four and a half years ago and all has been fine till now.

I was hoping maybe someone could offer some insight here. I would be thrilled if just replacing the memory would solve the issues, rather than having to get a new hard drive or at worst a whole new machine. Any help you can offer is greatly appreciated.....

Thanks!

Oh, here's the log from my last kernal panic:

Wed Jun 11 14:01:59 2008


Unresolved kernel trap(cpu 0): 0x300 - Data access DAR=0x0000000000000180 PC=0x00000000000A8A78
Latest crash info for cpu 0:
Exception state (sv=0x4FBBFC80)
PC=0x000A8A78; MSR=0x00001030; DAR=0x00000180; DSISR=0x40000000; LR=0x000A8A78; R1=0x370F3730; XCP=0x0000000C (0x300 - Data access)
Backtrace:
0x00034DBC 0x000329A0 0x00032E98 0x00026458 0x005007CC 0x00501B68
0x00502380 0x002BDA84 0x00A5C428 0x00A5BCFC 0x00A59F0C 0x00B6AAB4 0x00B77D04 0x00B77B30
0x00B65014 0x00B63ABC 0x00B63CF4 0x00B63E64 0x0003CA1C 0x000A9714
Kernel loadable modules in backtrace (with dependencies):
com.apple.driver.AppleFCU(1.3.2b0)@0xa58000
com.apple.driver.PowerMac7 2PlatformPlugin(1.8.6f1)@0xb71000
dependency: com.apple.driver.IOPlatformPluginFamily(1.8.6f1)@0xb60000
com.apple.driver.IOPlatformPluginFamily(1.8.6f1)@0xb60000
com.apple.driver.AppleI2C(3.5.0d2)@0x4ff000
Proceeding back via exception chain:
Exception state (sv=0x4FBBFC80)
previously dumped as "Latest" state. skipping...
Exception state (sv=0x4FA32780)
PC=0x00000000; MSR=0x0000D030; DAR=0x00000000; DSISR=0x00000000; LR=0x00000000; R1=0x00000000; XCP=0x00000000 (Unknown)

Kernel version:
Darwin Kernel Version 8.11.0: Wed Oct 10 18:26:00 PDT 2007; root:xnu-792.24.17~1/RELEASE_PPC
panic(cpu 0 caller 0xFFFF0003): 0x300 - Data access
Latest stack backtrace for cpu 0:
Backtrace:
0x000954F8 0x00095A10 0x00026898 0x000A8204 0x000ABB80
Proceeding back via exception chain:
Exception state (sv=0x4FBBFC80)
PC=0x000A8A78; MSR=0x00001030; DAR=0x00000180; DSISR=0x40000000; LR=0x000A8A78; R1=0x370F3730; XCP=0x0000000C (0x300 - Data access)
Backtrace:
0x00034DBC 0x000329A0 0x00032E98 0x00026458 0x005007CC 0x00501B68
0x00502380 0x002BDA84 0x00A5C428 0x00A5BCFC 0x00A59F0C 0x00B6AAB4 0x00B77D04 0x00B77B30
0x00B65014 0x00B63ABC 0x00B63CF4 0x00B63E64 0x0003CA1C 0x000A9714
Kernel loadable modules in backtrace (with dependencies):
com.apple.driver.AppleFCU(1.3.2b0)@0xa58000
com.apple.driver.PowerMac7 2PlatformPlugin(1.8.6f1)@0xb71000
dependency: com.apple.driver.IOPlatformPluginFamily(1.8.6f1)@0xb60000
com.apple.driver.IOPlatformPluginFamily(1.8.6f1)@0xb60000
com
*******