.pdf file o/p is not same size as native file

I've been having trouble with .pdf file output in both CorelDraw, WordPerfect and AI CS. The output file appears to be in a 'fit to page' type layout as it is always smaller than the page printed out of the native pgm. I have checked settings in the PDF printer driver and can find nothing that refers to a 'fit to page' type setting.

Any suggestions would be most welcome.

What printer are you using?

I currently use a HP Laserjet 1320, an Okidata Color Laser C3200 and a HP Color Laser 2605dn, and the print shop has some sort of large machine that prints, duplicates (like a copy machine) but also produces plates for offset printing. I don't know the model/name but can get it Monday. But I think I use a PDF printer driver when I create a .pdf file.