ok i have hit a wall and need some help please...

I just bought a brand new computer and a new ati radion 7500 64 mb. card. now i had an different card b4, a nvdia gf2 64 meg card and the same thing keeps happening, UT2003 keeps closing down on me, is there any suggestions of what could be the problem i have updated the drivers and i have gotten the new version of directX, and i have even updated ut, but i'm lost now, and am in need of serios help.

Jeff