http://bugs.winehq.org/show_bug.cgi?id=25077
--- Comment #6 from Vincent Povirk madewokherd@gmail.com 2010-11-11 10:53:44 CST --- This appears to be implemented: https://github.com/mono/mono/commit/1763dd12901167fb5e352383d109e0559adfc784
And it should be in Mono 2.6.7. Can you get a log with MONO_TRACE=T:Microsoft.Win32.Win32RegistryApi WINEDEBUG=reg,tid ?