Windows 7 - Game on single monitor only.

Not sure whats happening.All programs run with extended display mode,except portal 2.The game will only open if i select either monitor 1 or 2. (42" lcd samsung) (22" acer) ati radeon hd 6450 1 gb vram.Windows 7-32.samsung is hooked up via hdmi and acer using dvi.Both monitors are set to the same resolution and dpi as win 7 automatically recommends.The game runs flawlessly.All drivers are up to date.I dont want to view the game on both monitors,I just want to monitor my system on the smaller monitor with HWMONITOR while the game is running on the larger one.Ive tried all the osd recommendations and all the programs,but none seem compatible with my system to display sysyem stats while in game.Thanks.