I've got a user who has Project 2007 files stored in their MOSS 2007 team site. He checks out the file out and then says Edit in Microsoft Project. When the file opens, it opens in read only mode. In order to save changes, he has to save the file locally then upload it to the document library.
The user is using a Windows 7 VM inside a Mac with IE9. Any ideas why this happens? Other office documents in Office 2010 open without isue in edit mode.
Note: we are not using project server and it isn't displaying the message the file is locked for editing like most search results are coming up with.