When I try to open a file in Excel 2007 that has been exported using the ExportToExcel() function on a DataGrid, I get a message:

"The file you are trying to open, 'filename.xls', is in a different format than specified by the file extension. Verify that the file is not corrupted and is from a trusted source before opening the file. Do you want to open the file now?"

If I press 'Yes', it opens fine.  This didn't happen in Excel 2003.  Is there a fix for this?

This post shoudl explain all... http://xceed.com/CS/forums/post/24984.aspx

The export is in xml format - hence the warning message. If you name your export file blah.xml then the message will not be displayed.

Ah thanks. I did search for an answer using the search string "different format than specified by the file extension", but it didn't come up with the existing post because that post has typos in it for that same error message.  Emphasises the importance of spelling error messages correctly!

Thanks for your help.

Jason