Strange Excel Issue

I have a very strange Excel 2003 issue.

I have a user that receives several excel files via email attachment on a daily basis. She open all of the excel files except one, and it give the error (I've replaced the excel file name):

"Cannot create file: (excelfilename). Right click the folder you want to create the file in, and then click properties on the sortcut menu to check the permissions for the folder."

I've done this and she has full control of the Outlook temporary folder (she is also a local admin on this machine). I've also gone into excel and unchecked the "ignore other applications" box. I've edited the location of HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Security]"OutlookSecureTempFolder to point to a newly created temp folder that I know the user has full control over and none of these things have solved this problem.

I'm going to try and wipe out this users profile (actually I'm going to rename it) and then see if she can access this file or not.

This seems like a permissions issue, but I can't seem to pinpoint exactly what is going on.

Has anyone else dealt with this, and, if so, would you be willing to share what you have or have not found?

Thanks!