FCP5 Crashes Every Time I Render. Why?

Question

I've been having this problem as long as I've has this computer, but I can see no reason for it. If anyone has an answer, please, please, please offer some advice. I've worked in FCP 4.5 and 5.0.3, always with the same result: Every time I go to render a sequence, the system freezes up. Sometimes at 1%, sometimes at 55%, sometimes at 90%. It seems random. I'm working on a large project loaded with media (>160 GB, DV codec, about 1200 clips) and a number of 10 minute sequences. The media is on its own internal 200GB drive, other elements and render files go to another 120GB internal drive, and the system software is on its own 160GB internal drive.
Here's my system specs:
G4 Firewire 800 Model, Dual 1.42 GHz
2GB RAM
3 internal ATA drives
FCP 5.0.3
OS 10.4.2
Here's what I've done to fix it:
-reinstall system from scratch
-move around RAM to different slots
-repair permissions, trash preferences, FSCK -f, reset motherboard, zap PRAM, reset firmware, other utilities
-switch around internal hard drives (I found my Mac HD was on bus #2)
-render to a different drive (I've tried other internals and FW800 external)
-install a new motherboard (even though tech found nothing wrong with the original)
-start a new program and import all media in from the hard drive
-import sequences into new program from XML files
-create a new user account dedicated only to FCP
-test RAM and all hardware using Apple Hardware Tool (on a loop) and Tech Tool
-run Diskwarrior
I've tried everything I can think of, and clearly nothing works. I also tried opening this project on an old Powerbook G4 and connecting it to the media on a FW drive, AND opening it on a G5 with the media on a SATA RAID. Both of those worked fine, proving (at least to me) that its not the project. Could it be happening because the PowerMac can't handle the amount of media on the internal drive? Why would the laptop not have a problem then? Could the system just be a lemon and somehow not be able to deal with this?
If anyone has any idea please do offer your opinion. Thanks so much.

Answer 1

Welcome to the discussions, Wanderlust.
Based on your thorough troubleshooting, I'd have to suspect faulty RAM. This does not always show up in RAM tests. Moving RAM around doesn't stop it from failing. My wife's iMac kept locking up on her at random times. I tried testing her ram, checked all kinds of things. Based on all testing, there was nothing wrong with her hardware. As soon as I replaced her RAM, her lockups disappeared.
BTW, I have a MDD dual 1Ghz with 5 internal drives ranging from 250 GB to 120 and it has no problem coping with any of them. I'd try swapping out your ram.
Patrick