Duplication first monitor to 3rd? (my tv)

hey, im looking for a bit of help for my system. I run dual screen of my gtx470, and i wanted to connect my TV as well, so i can watch movies on it from my PC. However when i tried this though the mini hdmi port it said that it doesnt support 3 outputs from 1 card.

So i bought a cheapish card with a HDMI slot, i bought the gt 520. However once connected up, and on the nvidia control panel, i dnt get the option to duplcate onto the 3rd monitor.

Basicaly what i want to do is duplicate my main primmary monitor onto my TV. Is there a way i can do this?

Thanx

Ghost

If you don't mind loosing a monitor (your secondary) every time you watch tv, buy a dvi splitter with a manual switch.

When you are using the tv, flip the switch so your secondary dvi port goes to the tv and select duplicate in the nvidia control panel.

Or you could just use the mini hdmi and pull out or plug in the secondary dvi everytime you need to switch. You might even be able to leave them all plugged in and simply disable one or choose which ones you want through the nvidia control panel.

There might be a more elegant solution but i can't think of one. If you were using amd cards....

you can only sli identical cards.
ive never heard of anyone putting two different cards in for your reason. It might work, not sure how though.