PDF export prior to printing on Mac OSX Mountain Lion

I have set up a Print Configuration for my size and scale drawing sheet, then saved the file as a PDF, but when I go to File>Export>PDF Export and fill out the appropriate sheet size (using Model Space), I always get an error popup window that says: Error (1000a) Layout overall viewport is invalid.  The Print Preview looks perfect, but nothing is saved in PDF.  I have double-checked the print configuration using Print Configuration Manager, and it is correct.

I have saved to PDF recently using a different size paper and had no problem.  Does anyone have any idea what I am doing wrong?

OBO Debra M