CorelDRAW X3 Publish to PDF - Error "This file is already in use" & creates 1 kb PDF

Hello,

I am trying to help another user with a mysterious error with their CorelDRAW X3 Publish to PDF problem. Any tips appreciated. Here is what I know so far.

1. The problem occured last week with their CorelDRAW X3 on a Windows XP.
2. It have been without this problem for years, and just happened, last week.
3. They create a CorelDRAW X3 (I call computer 1) .CDR document.
4. And that .CDR document is fine and all their other computers (2,3,4) also using X3 can open the same file .CDR file with no issues at all.
   
   
5. NOW problem starts: On this specific computer 1 with X3, they create a PDF using Publish to PDF. And save the PDF file on their desktop.
6. And then later place it on a server, and all other computers can NOT open it - they used to be able to do it. None of their 4 computers can open it.
7. The PDF that was being created, for some reason, now only weigh 1 kb.
8. The PDF file they created in X3, also give a sort of "Error" saying "This file is already in use" when trying to open it on all computer
   
9. They have reinstalled CorelDRAW X3 on this computer 1, numerous times.
10. On Computer 1 (this computer) they only use the Factory Default interface. No customizing to the UI.