Videocard problems . . massive

[Scuzzie]

I've just put a secondhand videocard in and when I run MAME, (multiple arcade emulator), or windows media player, amongst others, the screen blacks out for a second or two . . can someone suggest where I should look to prevent this from happening. . the previous card was flawless heres some of the data on the problem
Pentium 3 - 650 ancient I know
128 meg ram
old card - Nvidea AGP - 7 years old
new card - GE Force FX 5200
Win 98SE

I had been mucking around with output to a TV when this started to occur

Any help would be appreciated
Thanks

 

[Simon]

Reinstall the Nvidia Drivers www.nvidia.com/driver