Switching Resolution to full screen in Widescreen problems (FIXED)

When i change resolution of the Demo to WideScreen Resolution in full screen, everyhing is rendered in Black (exept for skybox that works), as if Lighting stopped working.

This was tested with 2 different PCs.

ATHLON x 2 and ATI X1650
and
PHENOM x 4 and Nvidia Gefoce 9800 GT

In both machines DX was updated to the max, so were Card Drivers.

Is this bug already documented?, i couldn't find it on the search engine.

So basically i can't use Beta in other resolucion than default, Switching will get me this problem.