Excel '07 will not open files

When I double click on an excel file excel opens but the spreadsheet does not. If I do file>open the spreadsheet will come up.

I have already made sure the "ignore other apps" is unchecked and reregister the server. Any other ideas?

If anyone else ever has this problem....
Tools>Folder Options
click File Types, scroll to ".XLS", and click Advanced
Highlight "Open" and click edit
Uncheck "Use DDE" and click OK.

I don't know what i did but it worked.