http://bugs.winehq.org/show_bug.cgi?id=28158
--- Comment #5 from MestreLion wine@rodrigosilva.com 2011-08-22 19:44:12 CDT --- By the way, that commit is buggy (or incomplete): it only lowercase windows extension in generate_associations(), while it allows mixed-case in both build_native_mime_types() and freedesktop_mime_type_for_extension()
So it fails to find that *.Z is currently associated with application/x-compress and *.amr to audio/AMR in my *native* mime database, and creates duplicate entries for those, no matter how they are registered in windows.