gainward 7950 gx2 problem!

For starters i am running:

windows xp pro sp3
asus m2n4 sli motherboard (nforce 4 chipset)
4gb ram
amd athlon 64x2 4000+
gainward bliss 7950 gx2 1GB graphics (connected to 2 power supply leads linking from hard drive)
250GB seagate HD 7200 rpm
400W PSU

I am having great difficulty with my graphics card. i have installed the latest nvidia drivers, however when i click on the nvidia icon in the taskbar the screen flashes once or twice before showing the menu. also when i connect my tv to the 2nd dvi slot i can clone the desktop image from my monitor, but when trying to watch films, all i get is a blank black screened media player. the sound works but no video shows.

i have tried all sorts of different combinations of nvidia drivers with no success, even trying older drivers. i would try and flash the bios to a new version (asus bios update wont let me flash), but im not sure about using the dos function.

i have read numerous forums regarding this problem, and people suggest there is a driver conflict somewhere but i can't seem to find it.

any suggestions pleae before i go insane? cheers