Export to Excel - Open File Error

[Wendy]

We have recently upgraded to Office XP and the Access
programs that I currently have (Office 97) that export to
Excel then open Excel to format the reports don't work.
They export but won't open. Access gives me error
of "Method "Open" of object workbooks failed". Then when
I open the exported Excel file it says "Renamed invalid
sheet name" and it renames the sheet "Recovered_sheet1".
How can I get around this? I have to get my programs
running ASAP!! HELP!