I'm assuming your form letters are reports in Access. A common reason for
blank pages on reports is that the width of the report plus the margins is
greater than the actual width of the paper.
Look on the values for the left and right margins on the Margin tab under
File | Page Setup. Then, look at the width of the report. If that's greater
than 8.5" (or whatever width paper you're using), try to adjust them so that
they fit.
If you're trying to make the width narrower but can't, perhaps you have a
"hidden" control on the report that isn't apparent. If you've got lines,
they'll often be difficult to see, but they might extend too wide.