Do you have Compiz-Fusion enabled? Compiz-Fusion and the ATI driver don't work with videos or Google Earth under OpenGL (*). Right-click on the Compiz-Fusion Icon on the Panel and click on Select Window Manager > KWin (or Metacity) and then run Google Earth.
Also, to optimise the performance of the ATI fglrx driver try the xorg.conf settings given in the first post in the following thread:Setup an ATI card with the new FGLRX drivers for Compiz-Fusion
The same applies to watching videos: either switch to the KWin or Metacity window managers or select a video driver other than OpenGL in MPlayer/KMPlayer/SMPlayer/VLC etc. (e.g. X11/XImage/Shm, X11 video output etc.).
(* Support will come in some future release of X11 and the ATI driver, as the problem is a combination of code in both X11 and the ATI driver.)