Comment 4 for bug 1325814

I can confirm this behavior, but it is not confined to Update Manager.

Some programs besides Update Manager that give me this same problem

google-chrome, skype, freecad

In all cases the processes are running and the icons have menus that indicate the programs are running. Also the click again solution does *not* work for me. The click again will open a blank, menuless, full screen window, that only has the close icon ("x") active... sometimes, but not always.

tails of dmesg, nor syslog show any activity when these4 programs are started. nor are any log files in /var/log updated.

This began after a mid-August update, and one other curious bug that started at the same time was that clicking the fullscreen icon on nearly every video on the web would not work and blank ourt the video screen (burying and putting the browser window back on top brings the regular video back). The only place on the web wher this does not happen any more is directly from YouTube, embedded YouTube videos do not go full screen, btu they do when you are at YouTube.com.

I don not think this is a bug with Update Manager.