Hey I registered here to say that I'm having the same problem with this.
System specs:
Core i5 2500K 4.5GHz (stock or overclocked makes no difference)
8GB DDR3
Asus Essence STX
60GB SSD/1TB HDD
Silverstone 600W (strider plus)
Windows 7 Ult. x64
Problem:
(I am using the UniWS fix which doesn't work with the steam version because of encrypted executable, hence version 2.1.0.0 instead of 2.2.0.0 - it still happens either way)
I even have the same problem with the original kotor: