http://bugs.winehq.org/show_bug.cgi?id=3711
--- Comment #14 from Hans Leidekker hans@it.vu.nl 2008-04-06 08:09:52 --- I investigated the issue with FL Studio a bit more and found that it's a bug in the app after all. Apparently the registry value is created for the administrator user somewhere during Windows installation (presumably because it checks for updates or tries to register or something like that).
If you create a new user under Windows you'll find that the value does not exist, so FL Studio would give the same error under Windows. Running IE once makes the value appear though.