Adobe acrobat is not activated. Cannot create the PDF file.

Cannot create the PDF file.Getting the following error on the second time a PDF creation is attempted on Acrobat 11. 

"Adobe acrobat is not activated. Cannot create the PDF file."

Found on the web to close the Acrotray.exe process, but this is a temporary fix.  We are only seeing this recently on every install.  We've had Acrobat 11 out for about a year.  The license number being inserted into the install. 

Has anyone seen this before and what should I check?