cant play mass effect 2 and dragon age thru my hdmi

hi there
my specs are in my sig. and im using 186.81 nvidia drivers.
i can watch dvds blurays and other stuff using my hdmi connection to my sony bravia 720p 55inch 3lcd tv.
i can also play some games normally like COH and nba2k10.
however whenever ii play mass effect2 and dragon age, and i switch to 720p i encounter a whole lot of stutter, which makes the game unplayable.
when i switch to 1080p, the video card seems to scale the video, and i can still play, and amazingly with less stutter. however the desktop size goes a little beyond the screen border and therefore i cant use icons near the botton or top of the screen.
does anybody know whats goin on? and is there a fix for this? obviously it aint my gpu thats the problem. im also thinking it cant be my hdmi cable since i can play some other games on it.
im stumped.

 

Hmm I'm not sure what the issue could be. I was just playing ME2 on my 19" 1080p Vizio via HDMI the other day, with zero issues. I'm also using 186.81 Forceware.

 

yes it is very wierd.
i was thinking first that maybe mt hdmi cable couldnt take the number of bits being transferred but the wierd thing is im having probelms at 720p, which is the native res of my tv and not so much in 1080p