Yes, that did the trick.  I used your idea in many different tests that I have done and basically added the second of the following two lines and that seemed to do the trick.

Thank you!

...

Plane Surface(1) = {1};
Physical Surface(2) = {1};

Great!  You're welcome. 

So you didn't need the Physical Line…  I wonder if my warning about those being required all round were wrong or outdated… Let me check.