I'm sure you have moved on beyond this problem by now. However my users often report this phenomenon when the body dimensions extend (are wider than) the report layout dimenions. If your report layout is 8 1/2 long by 11 wide, with a one inch margin on the left & right, your report body can be no wider than 9 inches. When you export to pdf, the pages seem to grow beyond the preview mode. If you look at the number of pages in the print-preview mode you should see the real number of pages that will be printed or converted to pdf.

CJ