Conflict with Adobe Reader?

It used to be running fine for a while until recently after I installed a new version 1.2.1 it says, "There was an error opening this document saying, "This file is already in used or open by another another application.". This happened after it showed the password option.  Actually, I did not use or open another application at all.

Notre: Ghost script is 9.02


Should I clear cookies everytime I want to conver a doc file to pdf?