Another G5 kernal panic on start-up post - but this one is different!

Question

Hello all,
So, I purchased my g5 used, but I've had it for about three years now with no problems. Within the last few months, however, my G5 kernal panics on start-up about 25% of the time. Also, it has been freezing on wake-from-sleep, at one point about 75% of the time, but now the wake-from-sleep issue is at about 15%.
In May or so I installed some new Crucial memory.
In October I replaced the start-up drive from what I assume is the OEM Maxtar with a Seagate 250gb 7200.10. I removed a media HD from the 2nd HD slot and copied (using Disk Utlility) the OEM Maxtar drive to the new Seagate drive. At some point, I had copied the system folders to my media HD for back-up. When I installed the new Seagate, the computer would often boot to the media HD, even after selecting the Seagate as my start-up drive. However, despite being confused on several occasions, it always started up and never had a kernal panic - also, I didn't reset the PRAM and SMU until recently, so that might have solved that problem.
Until I installed Leopard. After installing 10.5 when it debuted, I started having frequent kernal panics on start-up and these wake-from-sleep problems. Both were more frequent then they are now, and sometimes I can go a week without either of these problems occuring.
The kernel panic that I get on start-up reads something to the effect of "Cannot find driver for this unit (Powermac 7,3)." When it KPs on wake, it points to the "ATA driver."
I have reset the SMU, but I have not tried reseating the RAM. I have run the RAM diagnostic . . . although I have only had the patience to get through one iteration.
I have repaired permissions and verified the disk from the Leopard install DVD.
Any ideas? Is it the HD? I get the feeling that the HD is not powering up when it needs to to provide the computer with the OS on power-up and wake. Perhaps Tiger was able to deal with this and with for it to get going, or the move to Leopard happened so close to the wiping of the OS from the media HD that I didn't notice it. But the thing that kills me is that it does not happen all the time!
Thanks!
CMF

Answer 1

The optical drive? Isn't that odd? It's the OEM Superdrive, as far as I know. Maybe there is a firmware update for it I'm missing? Here's the stats:
Model: PIONEER DVD-RW DVR-117D
Revision: B705
Also, I've included the KP data for the wake-from-sleep KPS:
Wed Dec 5 18:43:36 2007
panic(cpu 1 caller 0x00B786B4): "ATA Device recovery failed\n"@/SourceCache/IOATABlockStorage/IOATABlockStorage-200.1.8/IOATABlockSt orageDriverV2.cpp:2325
Latest stack backtrace for cpu 1:
Backtrace:
0x0009AD18 0x0009B6BC 0x00029DC4 0x00B786B4 0x00B788D4 0x007A50E8 0x007A581C 0x007A8CF8
0x007A9A14 0x007A8AF0 0x007A8774 0x00B97D58 0x007A8704 0x003566C0 0x007A86AC 0x00B97C98
0x007A3BAC 0x00B78624 0x00B78748 0x00B788D4 0x007A50E8 0x007A581C 0x007A8CF8 0x007A8F20
0x00B9A008 0x007A8E24 0x007B00B0 0x0003F8D8 0x000AFE54
Kernel loadable modules in backtrace (with dependencies):
com.apple.iokit.IOATABlockStorage(2.0.0)@0xb75000->0xb87fff
dependency: com.apple.iokit.IOATAFamily(1.7.3f1)@0x7a2000
dependency: com.apple.iokit.IOStorageFamily(1.5.2)@0x67c000
com.apple.driver.AppleK2SATA(1.0.4f2)@0xb96000->0xb9afff
dependency: com.apple.iokit.IOPCIFamily(2.4)@0x6ae000
dependency: com.apple.iokit.IOATAFamily(1.7.3f1)@0x7a2000
com.apple.iokit.IOATAFamily(1.7.3f1)@0x7a2000->0x7b3fff
Proceeding back via exception chain:
Exception state (sv=0x4ab01a00)
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