I have this problem. I have run the xwininfo (see below), and it's interesting to note that it says that is the gnome-calculator, but I don't even have a calculator open...!
xwininfo: Window id: 0x4e00004 "Calculadora" Absolute upper-left X: -1 Absolute upper-left Y: -29 Relative upper-left X: -1 Relative upper-left Y: -29 Width: 312 Height: 216 Depth: 24 Visual: 0x21 Visual Class: TrueColor Border width: 0 Class: InputOutput Colormap: 0x20 (installed) Bit Gravity State: NorthWestGravity Window Gravity State: NorthWestGravity Backing Store State: NotUseful Save Under State: no Map State: IsViewable Override Redirect State: no Corners: +-1+-29 -969+-29 -969-613 +-1-613 -geometry 312x216+-1+-29 -- You received this bug notification because you are a member of compiz packagers, which is subscribed to compiz in ubuntu. https://bugs.launchpad.net/bugs/709461 Title: Application windows can sometimes fail to display and will mask regions of the screen _______________________________________________ Mailing list: https://launchpad.net/~compiz Post to : compiz@lists.launchpad.net Unsubscribe : https://launchpad.net/~compiz More help : https://help.launchpad.net/ListHelp