Subject: Re: Very OT: Help with Mac-Win problem?
It is probably some sort of obscure permissions issue.

There are a couple of Windows command line commands that you can try. They solve all of my weird file problems.
Sorry, I don't have them at hand, but you can google them.
1st sets you as the owner of all files in a directory.
2nd removes all permission restrictions.

OTOH, I have run into another Windows file problem that I have not been able to fix. A file shows up in the directory listing but when I try to delete it, it says "No such file".