Take the tour ×  After I close a program, part of the window
remains open. The affected part of the screen remains as it was
when the window was open, and it stays on top of other windows.
It's not a redraw issue per se -- xrefresh doesn't help since it
repaints the bad window.  This phantom window does not appear in
the 'task bar' or Alt+Tab switcher, but it's not just a screen
artifact either. When I run my mouse over it the cursor changes,
so it's still being treated in some ways like a window (though
it can't be selected or changed and it doesn't have a full
titlebar).  Any ideas how I can change this? This problem
happens, unfortunately, with some regularity to me, maybe every
other week. As I leave my computer on for extended periods to do
extended calculations this is more than a small inconvenience,
since it blocks part of the display for several weeks until the
work is complete and I can restart.  share|improve this question
Please, tell us Ubuntu version, desktop environment, graphics
card model. – 