The problem seems to be consistent. If I have a doc open in flash and I undock the document from the tab header, then I Alt-tab to a different application, and when I Alt-tab back to Flash shortcuts doesn't work until I perform one of the workarounds posted here in this thread.
If I Alt-tab back to Flash while there are undocked document windows inside flash I get a flash icon for each flash document inside Windows' alt-tab window (ie. the window that appears when pressing alt-tab). If I choose the icon titled "Adobe Flash CS6" everything is fine and shortcuts still work. If I select an icon belonging to an open document in flash then shortcuts dont work anymore. 2b1af7f3a8