I have found that if I use LW to launch a successfully-downloaded file (such as from the Library) or if I use the Help menu to access the Forum or FAQ, then the appropriate application will operate without problems. From there, I can switch to the Finder and Hide Others from the application menu. The control strip also works without the problem occurring.

Obviously, I'm not happy with this behaviour, but having the workarounds described above at least lets me get on with my work.