This computer BSODs 3 or 4 times a day. I reinstalled windows last night, thinking that would probably clear up any software issues that would cause driver conflicts that may perhaps have led to one of my BSODs. No dice, though the install went perfectly smoothly.

Here are the BSODs i'm getting now. After I reinstalled, there were no issues while I installed programs and updated windows. Everything went off without a hitch. I got the first BSOD (PAGE_FAULT...) while downloading Gal Civ 2 and ripping an ISO. The others have followed within 1-2 hours of each other.

PAGE_FAULT_IN_NON_PAGED_AREA 0x50
This happened once. I did some research and I think I found teh culprit: old sound card drivers that I installed off of my motherboard disc. They've been upgraded. This is the first BSOD I've gotten after 10 hours of error-free computer operation.
PFN_LIST_CORRUPT 0x4E
This is the same as the one i got before i reinstalled windows, just different parameters. Windows says it's my RAM, or something is corrupting my IO drivers. What the hell? The only IO drivers i've installed are Microsoft's own Intellipoint drivers for my Microsoft Comfort Optical Mouse 3000.
IRQL_NOT_LESS_OR_EQUAL 0xA
This is another driver issue according to MS. I'm at a loss for what it could be. I'm going to try updating my chipset drivers first before rummaging through all of my other hardware drivers.

I spent 4 hours running memtest86. It ran though 6 complete batteries of tests and turned up 0 errors. Chances are, it's not my RAM that's the problem.

Any suggestions? I'm really at a loss here.