3DSM5 with Art tools crashes after a while

[xXMephistoXx]

I do some amateur modelling for Wc3, and I do it in 3DSM5 with art tools, ofcourse. Before, I had an old crappy computer, which I used for it. I just bought myself a new computer, real expencive on too... The thing is, when I run 3DSM5 too long, it just exits the program... It looks like it only happens when I'm holding down a button, or I'm moving/scaling/rotating/beveling and such... Does anyone have an idea what this might be? I have ATI CrossFire Screencard(<-- Is it called that?), but I tried do deactivate it, didn't do anything... If anyone knows about this, or have had the same problem, I would really appriciate it if you would help me out!
Thanks!

 

[DwarfZealot]

Screencard(<-- Is it called that?),

its called a video card

 

[xXMephistoXx]

Thanks for helping me out -_- ... OK, now I know that for another time... But, do you know anything about this problem?