I see this too after waking from suspend. The retained image was pixelated - it looks similar to TV noise. Mousing over the Ubuntu symbol caused the menu to come out again, which redrew the menu and it retracted normally.
I caught a photo of the pixelization. It happens pretty repeatedly after waking from suspend. Pic attached. ** Attachment added: "pixelization" https://bugs.launchpad.net/unity/+bug/676166/+attachment/1980819/+files/IMG_20110404_073627_modified.jpg -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/676166 Title: Screen corruption when resuming from suspend -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs