Excel 2003 crashes when saving in Excel 2007

[jmcqup]

Hi. We are in a pickle! My colleague and I are working on a 50+MB file that works fine in Excel 2003 but crashes on SAVE or SAVE AS in Excel 2007 -- it opens fine and changes can be made until saving.... We have tried Stellar Pheonix Excel Repair tool without success and before rebuilding need to understand what could be causing the problem -- lest we just create the same problem again. Grateful for suggestions. -james