Microsoft Office Excel has encountered a problem and needs to close
 

Hi,

we have recently upgraded from Office 2003 to Office 2007. Our users
are using some Excel files created in Excel 2003. These files contain
some code in VBA.
There is a CLOSE button on the form and when they hit on that close
button excel is araising the following exception. The code behind
close button is simple (ActiveWorkbook.Close SaveChanges:=False).

"Microsoft Office Excel has encountered a problem and needs to close.
We are sorry for the inconvenience."

I dont get this error when 2003 is used.

How can I solve this problem?

Thanks