Error when converting office files to .pdf

I know that question has been asked on the internet before, but I have not found an answer. Here is the issue.
Using XP, Office 2003. Receiving the following error when converting office files to .pdf: "There was an error opening this document. The document cannot be found". The office file does, indeed, get converted and put in the correct directory, but we get this error each and every time. We have to End Task to make the error go away. It still works, but the user finds this "error" very annoying. Any ideas? Thanks so much!