Can't save changes
 

I'm using Excel 2003 and I've got a spreadsheet (aprox 8400 rows x 20
columns) with 5 other tabs of data (not very large) of supporting data, and I
get a message that reads:
"Excel could not save all the data and formatting you recently added to (My
Filename).xls" when I try to save some changes. I select "Help" and get a
blank window. I've tried clearing all columns and rows outside of my data to
no avail. Does anyone have any suggestions? I really don't want to loose all
of my formatting.