Video Card Problem

Okay, I just installed a G-Force 7500…(256 meg)
The graphics look great, I am running dual monitors fine. BUT ALL of my DV capture programs lock up and won’t run. What’s up with that?

I hook up my camcorder, hit play, I SEE the video playing, but when I choose “capture” the program freezes…
I am also having a few other generic performance issues.