PDF's IMpossible to OPen and SEe in Sharepoint

I am an executive with 2 people working on Sharepoint. Both are using XP but one uses Office 2003 and the other Office 2007. When the 2007 person goes on Sharepoint and tries to open a PDF they get this message: There was an error opening this document. The filename, directory name, or volume label syntax was wrong. The document might be called 008 01 Keynote Brochure.
 
The second person is experiencing a different problem...when she goes into Sharepoint she cannot see PDF files that the first person has left for her at all.
 
This is very frustrating and would appreciate an email response at [link=mailto:msong [at] cohesiveknowledge [dot] com.]msong [at] cohesiveknowledge [dot] com.[/link]
 
OR call at 203-457-0444.