I wonder if you've got "selected items only" saved as the default?

Try edit : select all before trying to make the PDF.

If that isn't the answer, use the object manager to make sure the items are displayable and printable.

If the design is entirely text-only, try converting it to curves first. That shouldn't be necessary, but sometimes poor quality fonts don't PDF or print properly.

Failing that -- its probably time to check you have the latest X3 updates installed, and/or to reinstall.  

Is your image on the page, or outside it? Have had that problem with pdf files before; make sure that your page size is accurate and appropriate for the image size. Try some test runs with simple files w/no text or anything fancy to see if it's maybe the software.
good luck!
-E

'There is no LEASH LAW for the IMAGINATION!'
myspace.com/erixworx

I sometimes have problems creating pdfs from CorelX3 and find one solution is to go File > Print > Acrobat Distiller, save as a .ps file.  Then open Distiller, open the .ps file and it will create the pdf.  Obviously you need Acrobat Professional to do this.

There are third party alternatives to distiller, including DeskPDF which is available for free trial and about $20 to register.

However, CorelDraw's built in "publish to PDF" should work fine in most instances and the third party tools will probably struggle equally hard if defective fonts or other problems prevent publish to pdf from working.