Vista Media Center Very Jumpy

I have a Gateway GM 5260 dual core intel 6300, upgraded to 4gigs ram. I'm
running a dual monitor setup (22 inch Gateway and 19 inch Viewsonic both
running at native resolution). When I try to run Vista media center, it
drops frames like crazy, so much as to be unusable. I've tried running it
on either monitor with the same results, along with the annoyance of having
the mouse locked on whatever monitor it is running on. I've streamlined my
startup as much as possible so I'm baffled. This computer has plenty of
power and should breeze through media center. Is the dual monitor
overtaxing the anemic LE 7300 video card that comes with this gateway? Any
suggestions would really be appreciated.

Thanks,
Neil