Thanks Bob.

For anyone else experiening this problem...I solved it by doing what I do whenever I have a problem with any other software program: I shut down the computer. Wait 30 seconds. Restart.

Now everything is fine. This is also what he suggests (in the manual) for the initial install. Which I did. But since I had to alter some settings in the ini files, it stands to reason that I would have to repeat the restart.

I now have Zen installed and am learning the nuances of the program.