Menu rendering is not reliable.

Release : Ubuntu 10.10 x64
Video card : Radeon 9600 pro.
Screen shot : http://ubuntu-virginia.ubuntuforums.org/showthread.php?t=1675355 (first post)

Applications where this has been seen
Eclipse
Simple desktop menu selection

When selecting an entry from the applications menu, the sub menu opens, when the mouse exits the screen area it is sometimes not cleanup up. Only quitting the parent application can then refresh the screen area.

Application windows always appear behind these artifacts making the desktop unusable.

xorg.conf

Section "Module"
        Load "i2c"
        Load "bitmap"
        Load "ddc"
        Load "dri"
        Load "extmod"
        Load "freetype"
        Load "glx"
        Load "int10"
        Load "type1"
        Load "vbe"
EndSection

Section "Screen"
 Identifier "Configured Screen Device"
 Device "Configured Video Device"
 SubSection "Display"
  Virtual 2560 1024
 EndSubSection
EndSection

Section "Device"
 Identifier "Configured Video Device"
        Option "AGPMode" "4"
 Option "AGPFastWrite" "yes"
 Option "GARTSize" "64"
 Option "BusType" "AGP"
        Option "AccelMethod" "EXA"
        Option "AccelDFS" "true"
 Option "MigrationHeuristic" "greedy"
 Option "EnablePageFlip" "true"
 Option "EnableDepthMoves" "true"
        Option "OpenGLOverlay" "off"
        Option "VideoOverlay" "on"
        Option "ColorTiling" "true"
 Option "AddARGBGLXVisuals" "true"
        Option "RenderAccel" "on"
        Option "AllowGLXWithComposite" "true"
 Option "OverlayOnCRTC1" "on"
        Option "OverlayOnCRTC2" "on"
 Option "MergedFB" "true"
EndSection

Section "DRI"
 Mode 0666
EndSection

Section "Extensions"
 Option "Composite" "Enable"
EndSection