http://bugs.winehq.org/show_bug.cgi?id=21385
--- Comment #19 from zid zidsoft@gmail.com 2010-01-17 07:03:36 --- You're quite right, thanks for this. There's a group that user should be in. I managed to not hit the right behaviour as root because he has no D: and hit it as my user because of the group permissions.
Can't believe I haven't hit this issue earlier.