On my regular PC It lets me go to full screen but when I go to Photobucket the color pictures with the geek tab. The screen will be half light blue and half white diagonally. It also wont let me go to full screen on Youtube too.
For the youtube one, first you go on the center of the video screen then right click and press setting. Then on the lower most left there's a computer screen icon- click on it. Then uncheck the enable hardware accleration box. That should do it.