Description of problem: Once you start up virt-manager 0.2.1-1, one of the options under the File menu is "Restore Saved Machine...". Clicking on "Restore Saved Machine" and then clicking the "Cancel" button (or the X in the upper right-hand corner) in the resulting file dialog box causes the whole application to lock up.
Initial investigation suggests that there is some threading deadlock issue in the GNOME VFS library causing this problem. cf bug 206058
bug 206058 was resolved in libgnomeui-2.16.0-2.fc6, and I have verified that the virt-manager hang no longer occurs when this updated libgnomeui is installed.