Refreshing 2003 Pivot Table w/ Excel 2007
 

I have a pivot table created with Excel 2003. The source data for the pivot
table is an Access 2003 database query. When I open the 2003 workbook in
Excel 2007, it opens in compatibility mode as expected. When I refresh the
pivot table and attempt to save the workbook, I receive the following note
from the compatibility checker:

A PivotTable in this workbook exceeds former limits and will be lost if
saved to an earlier format. Only PivotTables created in Compatibility Mode
will work in earlier versions of Excel.

This confuses me because I am in compatibility mode when I save the
workbook. My other legacy pivot tables do not have this issue. On top of
that, if I get my colleague who hasn't been upgraded to Office 2007 yet to
open the workbook, refresh the pivot table, and save it, there are no errors
or problems with the pivot table. If some limit is being exceeded, as the
note above suggests, then I would think that he would encounter some issue.

Help me please. Until everyone I work with is upgraded to 2007, these
workbooks must remain in 2003. Hopefully we are talking about weeks not
months.