Computer locks up with captured AVI files

[Bullworth]

I upgraded my processor to a 1.4 T-Bird and since then my computer will almost always lock up with large AVI files. If I use the player in AVI IO they work OK but if I try to play them in Media Player or process them in VirtualDub the system locks up.
Right now I'm going to check the HD since freakin' Western Digital sent me a refurbished drive as a replacement. I'm also going to try different cables. Is there anything else I can also try. My system specs are:
Abit KT7-RAID w.BIOS V64 1.4 T-Bird
Antec 400W PSU
256 PC150 RAM
WD Caviar 8.4G
IBM 75GXP 30G
Plextor 12/10/32A
Mitsumi 32X CDROM
Asus v7700 Pure
ATI AIW 128 Pro PCI
Turle Beach Santa Cruz
Creative Modem Blaster
Windows 98SE
All drivers are up to date.

[zaki]

When you mean large, how large? I assume you know that FAT32 file system has a avi filesize limit of 4 GB. I also noticed that for files larger than 2 GB, WMP locks up and the PC needs to be rebooted. If I played using a DVD player program for example, it works fine (as long as the filesize is < 4 GB).