Ive been having an odd error come up pretty regularly.

IRQL NOT LESS OR EQUAL as well as occasionally getting a BAD POOL CALLER Bsod. Comes up every 20 mins or so, or randomly.

I understand this might be a hardware problem, so I ran memcheck as well as a Hard Drive diagnostic from Western Digital. No problems at all. Cleaned out the hardware (as it was quite dusty) and checked connections.. still Bsod. Even checked to make sure IRQ channels werent being shared. I noticed that two were for my Sata drive, but once I got them on their own channels, same BSOD. Read other places that it could be sound card issue, so I removed the sound card. Same problem. Also disabled onboard sound, to no avail.

I tried doing a fresh install of windows xp pro SP2. After getting the base drivers in, it started crashing rather quickly. I didnt have this problem when I first installed the drivers, only after a few months did it do this. It could still be an issue with the IRQ channels, but as im having a hard time assigning them their own channel Im not sure what to do.

Ive read that it could be a norton antivirus problem, but I dont use it. I also didnt install the Nvidia firewall. Im not sure if its a chipset issue with the Nforce 4, but I honestly have no idea.

Any help would be immensely appreciated. Ive literally wracked by brains trying to see what the problem could be.

The Setup:
Athlonx 64 X2 3800+
Foxconn NF4SK8AA-8KRS Socket 939 NVIDIA nForce4 SLI ATX AMD Motherboard
Biostar Geforce 7600 GS 256 Meg. PciX16
Crucial Ballistix 1024MB DDR400
Western Digital Caviar SE 120GB Sata-II HD
MSI 460 Watt PS