Losing hdmi signal (Toshiba 42AV500)

[qanda]This thread is about the Toshiba 42AV500. Click here to see full specs[/qanda]toshiba 42" lcd
cable box - connected through s-video
pc - connected through “dvi to hdmi” converter
when i switch input from hdmi to s-video and back, i sometimes loose signal to my hdmi
the only way to get it back is by unplugging the hdmi or restarting the pc

v card - nvidia 8400gs (latest driver)
any solution for this
anyway i can fool my dvi output to alway think hdmi is alway active

Don’t switch?
This is a common issue with DVI