This is a Windows problem that's annoyed me in the past - Windows (or at least XP) seems to think all folders are Read-Only, but allows them to be written to nonetheless.

There's an explanation of this here:

http://support.microsoft.com/kb/326549


note:
Quote:

"Unlike the Read-only attribute for a file, the Read-only attribute for a folder is typically ignored by Windows, Windows components and accessories, and other programs. For example, you can delete, rename, and change a folder with the Read-only attribute by using Windows Explorer. "



I don't think this can be the cause of the problem.