NVidia - setting up multiple displays via HDMI switch

[t0n1k]

I'm having an issue connecting my GTX to a Samsung 42" plasma via 4 port switch. There is no issue when the HDMI is plugged in directly to the TV, as the GTX recognises the TV as a "Samsung PDP" via setting up multiple displays. As soon as the switch is brought into the loop, no secondary display is detected. Any ideas how I can get round that? The other HDMI devices on the switch are powered down.