http://bugs.winehq.org/show_bug.cgi?id=13553
--- Comment #3 from Karl Relton karllinuxtest.relton@ntlworld.com 2008-05-31 06:05:23 --- It seems I was wrong about which version it last worked in - since I tried 0.9.49 and it had the same problem.
This means the issue came in much earlier - I'll keep hunting.
Meanwhile I have narrowed it down to somewhere in shell32 shlwapi setupapi shfolder