I have an excel file that won't let me save changes because it is Read Only. If I say save anyway, it creates a Copy of the file, then doesn't let me save that either because it is read-only. Sometimes it tells me that there is another copy open (there isn't). The file properties do not show the file as read only.

I am using Office 2007 with W7. I also tried on Office 2003 with W7, same thing. Driving me crazy.