A family of Microsoft relational database management systems designed for ease of use.
I had the same issue on Access 2007 when I migrated to Windows 7.
The strange thing was that sometimes it worked, other times it didn't.
If I kept trying to export to PDF, eventually it would do as it was told and I'd get an exported PDF.
What I found was that if the file already existed, the PDF would save as expected.
To get around the issue, I wrote a macro to firstly create an empty file then output as PDF.
Here's my code:
Dim fs As Object
Dim TextFile As Object
Set fs = CreateObject("Scripting.FileSystemObject")
Set TextFile = fs.CreateTextFile(DestPDF, True)
TextFile.Close
DoCmd.OutputTo acOutputReport, MyReportName, acFormatPDF, DestPDF
Good luck!