No it doesn't 'prevent' you from doing it, but I honestly don't know why you would want to do that with 1/3 of the desktop missing; either that or I am just not understanding what you are asking here. There is a reason why it's called the TRIPLEHEAD to go. If you want dual monitor support then just use both the dvi outputs on your card. Good luck.
LOL i know that 1/3rd would be missing, i'm just curious if it's possible.
For one reason, because i could use DH2Go instead of TH2Go, but why spend the extra cash for an upgrade later? If i could play *some* games to see how i like it with 1/3rd of the screen missing (games with HUD center) i.....i don't know, honestly i was just curious if you could.