mplayer window moving to the left when switching between workspaces

[Albert Vilella]

I noticed on my Ubuntu 12.04 32-bit that when I have an mplayer window open on a workspace with the right hand edge of the window at the right edge of the screen, if I then navigate to other workspaces and go back to the workspace where the mplayer window is, the window will move a few pixels to the left, not being placed exactly at the right edge of the screen anymore. If I move the screen back to the right edge and navigate through the workspaces again, it will move a few pixels to the left again.

It only happens with mplayer windows, does not happen with cvlc. Any ideas on how to solve this annoying glitch?

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: mplayer 2:1.0~rc4.dfsg1+svn34540-1
ProcVersionSignature: Ubuntu 3.2.0-39.62-generic-pae 3.2.39
Uname: Linux 3.2.0-39-generic-pae i686
ApportVersion: 2.0.1-0ubuntu17.1
Architecture: i386
Date: Mon Apr 1 10:49:16 2013
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423)
MarkForUpload: True
SourcePackage: mplayer
UpgradeStatus: No upgrade log present (probably fresh install)