We have a workbook that we have been using daily for many years in Excel 2003.

We are now migrating to Excel 2010, and have encountered the following problem.

When the workbook is opened in 2010 (32-bit version on 64-bit Windows 7) (clean open, no other workbooks present) and we try calculating any of the worksheets (even the simplest one), we get the following error:

"Microsoft Excel cannot calculate a formula. There is a circular reference in an open workbook, but the references that cause it cannot be listed for you. Try editing the last formula you entered or removing it with the Undo command."

This does not seem to happen in the 64-bit version of 2010.

If we open the workbook in Excel 2003, there are no calculation issues. If we open the workbook in 2003 and calculate one sheet (shift-F9), or even calculate one cell that is a trivial reference to another cell (=E4), and then save the workbook, we do not get quite the same behaviour: when opened in 2010, we can calculate various sheets (shift-F9 or worksheet.calculate), but when running a macro to calculate all sheets in the workbook, it crashes at some point on one of the sheets. Again, this does not happen in the 64-bit version of 2010.

Has anyone else encountered this problem with Excel 2003-workbooks in Excel 2010, 32-bit version? I cannot find any references to a problem of this description anywhere. Thanks.