I got the same problem, the 1.09 lockup after a hour or 2. 89 % Cpu use. byt after 1.11 update it lockup after 30 sek, high cpu util, and lots of treads. the best version was 1.0 some have it is getting worse.
My config is win2000 adv server. 850 Mhz Athlon, 640 Mb ram alot of disk. run like a dream, byt xolox !!(not so good).
Please its a great program really great. byt it is very buggy.