MSI Neo2 865PE FISR IDE Drives

Hello, I currently have 2 drives plugged into IDE1, 2 in IDE2 and 2 in IDE3. Whenever I have a drive plugged into IDE3 I have issues with my PC being unstable. I recently was noticing what i thought were issues with my RAM which after much playing around, came to find that when I would unplug the drives from IDE3 the RAM would check out and the PC seems to work fine. why can't i have drives plugged into IDE3? I have purchased a new power supply thinking maybe there was some power issues but that has not solved it either. I have tried 3 different brands of varying sizes from 40gig drives to 200gig drives. Also, i did upgrade the bios to 2.5 in this machine thinking the latest release may fix it but it did not.

Here are my machine specs if this helps:

865 Neo2 FIS2R 1gig Geil DDr 400mhz RAM 512MB off brand DDR 400mhz RAM DVD-ROM ATI 9600xt Video Card AGP Antec TruePower 430Watt PSU 2-200gig WD IDE Drives 1-160gig Maxtor IDE Drive 1-120gig WD IDE Drive 1-80gig WD IDE Drive

I have also tried some miscellaneous 40gig drives I have laying around with the same result. The old power supplies I tried was a 400 watt and a 380 both yielding the same result. Ideally this is what I would like to run above but with IDE3 not seeming to operate I can't get all of the drives working. It does seem that when I plug my dvd-rom into ide3 that errors go away and it works but that seems strange. Any ideas? Thanks for the help.