If I output a Management Reporter file to Excel, when I open it (using Excel 2007 SP2) I get the following message:
Excel found unreadable content in 'file.xlsx' (the name of the file). Do you want to recover the contents of this workbook?
If I say 'yes', the following displays:
Excel was able to open the file by repairing or removing the unreadable content.
Repaired Records: Cell information from /xl/worksheets/sheet1.xml part
The Excel file is then opened and it seems to be OK (I haven't done a detailed analysis yet, though).
We're running Excel 2007 on both the workstation & server, and both are at SP2.