title: emacs won't repaint buffer (windows 7)
body: <p>I am using GNU Emacs 24.2.1 on 64-bit Windows 7. Sometimes emacs window goes blank. This usually happens when switching focus back to emacs from another window. The only way to get the content back is to switch to another buffer and then back. No other programs behave like this. I do not have this problem on my home PC with similar hardware and OS.</p>