Continuing Kernal Panic, Mac Store Clueless

Question

I brought my 1.25 Dual G4 (MMD) to the local Mac Store because it had started having repeating Kernal Panics. The machine would run for 1-2 hours and then Kernal Panic. At times, the machine would even Kernal Panic at start up. I even tried starting off the 10.3.9 disk and it Kernal Panic'ed. In short order, I had no access to my machine, or even any way to save my info off my drives.
I am the guy that other people bring thier Mac to when it's broken. I have every program/tool needed to work on a mac. So if I couldn't find the issue, I surmized no one else could, and I may have been right.
I brought my G4 to the Mac Store. They were able to repeat the Kernal Panic, and were unable to get my machine up, even trying to fire it up off of an external HD. The Mac store changed my CPU ( $600.00+ due to my applecare expiring). That didn't do it. I took it home and it did start up, so I backed up onto a Firewire drive - BUT, one hour after backing up - KERNAL PANIC!
Mac Store Trip #2, they replaced my mother board (Logic board for mac users) and my processor again (free). 1 hour later KERNAL PANIC!!
Mac Store Trip #3 - they claim the figured out that a 3rd party HD I installed was causing the Kernal Panic. I took out the hardrive, bought a brand new one, reinstalled everything, 1 hour after I finished installing 10.4.7 BOOM KERNAL PANIC!
The apple store was clueless the whole time, and did about $2000.00 worth of repairs and labor for about 6 days costing me $600.00 and gas money. I really don't care, as long as my box works.
I have found that my fan doesn't seem to "speed up" anymore as it once did, and the inside of the box seems unusally hot. I just intalled 2 extra fans, and 2 hours later KERNAL PANIC.
I know the issue is not the HD. I know the issue isn't the video/3D card (I have 2 cards, and swaping them, both occur).
I have a 2096 SCSI card from adaptec with the driver installed that I have used for 3 years...dunno if it can be that.
I have a Aurora Fuse Igniter video card, with currently no driver installed. I'm gonna take that out, but that has been in the machine for 3 years as well, with no issues.
I can guess that MAYBE one of my ram chips has gone bad. I will try taking out all but the original ram and running the machine.
Any other ideas? Anytime the processor has to work hard for about an hour, the machine Kernal Panics. I have to admit, at least now it starts up - whereas before it wasn't even doing that - so the Mac Store did do something. Now the symtoms have just changed.
I am considering installing a 3rd fan that is attached to the HD case and pointed on a slight angle into the giant heat sink of the processor. The heat sink is right next to the HD, and seems to get unusally hot.
I have Geforc4MX card currently installed, and I own a 9800Radion Pro.
This box was my workhorse. I have owned about 9 macs, and I have never had real issues like this. Ususally my HD's would just die. I cannot figure out what the heck is wrong with it, despite 10 years of fixing my macs, friends macs, and family's macs.
The Kernal panic messages weren't even being saved, thats how bad the panic was. The few times I saw it, it said "CPU 01" but since the CPU has been changed twice now, I assume its not that.
Any suggestions would be helpful.

Answer 1

This may or may not help. I have experienced kernel panics periodically, daily, since I bought my 1.42 dual. I usually know how to fix things, but i am not certified. I understand heat, so I run a large fan- a real ordinary box fan- right next to my computer blowing past it. This does not strain the internal power supply further. i have the box maxed, two optical drives, 128 radeon 9800 card, 4 drives, no pci fans internally, unless you count the onboard video card fan. I don't leave my firewire drives attached- just on and off for transfers- and I was determined this week to get the problem (of 2 years plus, now), solved. I have been kernel panic free for slightly over a day, so I don't know if this is appropriate yet, but it seems that my original 1 GB of ram from the apple build was the problem. I did notice that those sticks were much hotter than my additional ramjet sticks this last week when I went to unseat and reseat them, so I just took them out as a test. I think formerly I just removed my additional ram as a test. I am looking around at the sticks to try and figure out if one duo was ecc and one was not.... but as I understand it, all that would do would be to remove the ecc function on the duo that was ecc... I do not remember buying non-ecc ram. If my machine continues to be stable, I intend to just buy a little more ram identical to the sticks that are working now. I've lost work and had continual challenges because of this problem, and it does not seem to be because of the ram I added, at all, but the ram from apple that I started off with. I have had this problem since the day i turned on the machine, I have read about so many other people suffering with it, and heat and firewire disks and power supply were the culprits always suggested to me. Does anyone have a site to suggest that helps one identify ram sticks with an image? Has anyone ever seen information from Apple that admits to this problem in these machines? They weren't continued that long with the move to the G5.