XBMC window is restored down

Hi,

Just got a new HTPC running Win 7 with XBMC 12.2 + Pioneer vsx-520 receiver, connected to a Samsung LCD TV. Here's my problem:

• I start XBMC in full-screen mode.
• Now, I change the source in the receiver (e.g. move to a DVD player connected to the same receiver).
• Now, I change the source in the receiver and move back to the HTPC.
• The XBMC window is now restored down (like if you click the "restore down" button that you have on the top right side of a standard window). I don't see XBMC in full-screen mode. The XBMC window now covers ~30% of the screen.
• I tried the same test with another window (e.g a maximized Windows explorer window), changed the source in the receiver, changed back to the HTPC, and got the same result - the Windows explorer window is not in full-screen mode.
  

This is annoying because I have to close XBMC and reopen it in order to get it back to full-screen mode.

Any ideas?

Thanks,
Erez