Please describe the problem:
When Rhythmbox is open, mplayer cannot go fullscreen correctly, when rhythmbox is closed, mplayer goes to fullscreen normally

Steps to reproduce:
1. Open Rhythmbox
2. Open mplayer
3. put mplayer in full screen mode, note how it is not functioning correctly


Actual results:
Mplayer can't streach the video to fit the screen, so it appears small 

Expected results:
mplayer to go to fullscreen normally

Does this happen every time?
yes

Other information:
I filed it here because its this which is messing up mplayer, so its rhythbox's fault.