Tv-card problems

I bought a Hauppauge Theater tv card, but i can only watch tv at a small size (about 320*???), if i make the window larger, many black points or stripes appear (on moving sequences). If i change my resolution to 640*480, i can watch full screen, but that doesn't look good (on 19" ) and i can't work with that resolution so i always have to change it back to the resolution i want (1600*1200).
Is this cause of my program (WinTV 32 and 2k) or something wrong with my video card (riva tnt2 32meg). I downloaded all new drivers available for all hard and software i have, but nothing helped.

It should have that option, it.s one of the most expencive cards around {in belgium}

... qwerty sucks, can.t find the buttons i need

WinXP will never show a blue screen anymore ... you need activation for that.