Vista - Windowed mode

My Media Center refuses to play in windowed mode. When I hit the center button (windowed mode) it acts like the minimize button. In the setup settings I do not have the media center in front setting checked. A while back the windowed mode did work, and then one day it stopped working. Can anybody help me on this?

Actually it doesn't act exactly like it is minimized. When I right click on the Windows Media Center tab on the bottom of the screen, it gives me the "size" and "move" options. When I select one of the the cursor appears in the top left corner in the four directional format, but the cursor returns to the arrow when I left click it, and nothing else happens. Basically it acts like it is windowed, but isn't. If I select cascade windows, or stacked, it behaves like Media Center is windowed right along with other windows, but it doesn't display.