I have an issue with my monitor setup and cannot play some new games.

Im running an ILO 32HD tv as monitor with an HDMI hookup. when I start some games and the application changes to a different resolution(?) my tv displays a 'no signal' message.

Portal 2 works, and my tv notes that it has changed to 1080p.
Is there a setting I need to change for these games to work?

thanks!