I reinstalled the AMD dual core optimizer and processor drivers for my Athlon processor and it seemed to have fixed my issue. In particular, I reinstalled these 2 files:
7/31/2008 AMD Dual-Core Optimizer Version 1.1.4
8/31/2007 AMD Processor Driver Version 1.3.2.0053 for Windows XP and Windows Server 2003 (x86 and x64)
They were already installed on my machine so I don't know why reinstalling these would correct my issue, but eh, whatever
The only game issue I've run into so far is Quickload loading Quicksave character data except with another savegame's character location (although if I manually load the Quickload save file it is fine).
