If you are exporting data from Payback to Excel you may sometimes experience a corrupt Excel file (i.e. when you attempt to open it in Excel, it is reported as corrupt / unrepairable)
To fix this issue, please exit Payback, and then download and run the following file;
http://www.payback.ie/downloads/ar2StdSP2.5.0.1309.exe(When you run it it will take you through an installation wizard)
This will update the reporting component in your version of Payback and make it compatible with your version of Excel.