Description of problem:
If you start virt-manager, and click Help->About, the resulting dialog box can
be closed by clicking the X in the upper right-hand corner, but not by clicking
the "Close" button in the lower right-hand corner.
Looks like we weren't handling the 'response' event in the about dialog
correctly so the close button wasn't getting processed.
Fixed in rawhide, virt-manager-0.2.2-1.fc6