I can't think of a solution except to use a target for the links in the iframe files which will open the link full screen instead of inside the same iframe that doesn't have enough height.
target="_new" or target="_blank" (new window), target="_parent" (parent of current frame, often full window if you don't have nested framesets) and target="_top" (loads in the full body of the window)
See
http://www.wickham43.net/framesets.php
Edit: on second thoughts that only works if you can code the target into the page link, but if it's a page from another source which you don't control you can't do that.
Last edited by Wickham; 31 Mar 2008 at 01:57 AM.
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.