cant get fullscreen video on tv-out

> I have my tv hooked up as a seperate monitor.im using the extended desktop
> feature to drag the video over to the tv. If i try to swich to fullscreen

> hitting alt+enter it swiches to fullscreen but also swiches back to the
> monitor. This used to work fine but now it wont. If anyone knows how to

> this or knows another way to get video on a second monitor your help would
> be appriciated.
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