Black / no video playback on 2nd LED monitor

Hi guys,

Have a frustrating problem trying to play My TV video software on a second LED 20' screen. No problem on the primary LED.

I built a new i5 system and all worked fine before I updated Windows 7 Professional. Dragging / playing it to the 2nd screen had absolutely no problem.

Graphics Configuration:
Palit Nvidia GTX460 Sonic (latest driver 306.23)
Primary LED monitor is on DVI and 2nd is on VGA
Both Samsung LED 20" monitors use the same default settings (on GPU)

TV card is a Chronos analogue USB dongle / software is MY TV 2.1

I tried CHrisTV software (if called that) and experienced the same problem.

I tried various settings on Win 7 / GPU, but same result.

Windows default video works on both monitors.

Anybody with a solution please...?

Thanks

Vernon Chalmers