All the memory is good, I have switched out the 512MB with the working configuration and it is fine. I think it is a memory "loading" problem, with posting the video card.
I will try rolling back to my previous nVidia driver this week end (so if anything goes wrong I will be able to fix it!
I was using a beta driver as I found the 44.03 driver unstable ! I never had a problem with the beta driver.
But I just got up to this much memory. I was going for the complete 4GIG set-up. but untill I solve the problems for 3GIG, I will wait to buy two more 1GB sticks!!
Tyan Tiger S2466N-4M motherboard.
Dual AMD 2400+ MP CPU's
Gainward FX PowerPack Ultra/780 TV/DVI (Geforce FX5600 256MB DDR)
3 Gigabytes PC2100 DDR RAM ECC Registered
Dual DVD's (one recordable)
3.5" Floppy 1.44MB - two hard drives ~ 80 GB total.
NEC MultiSync LCD1700M+ Monitor.
Santa Cruz 5.1 sound card with 5.1 speakers & woofer.