http://bugs.winehq.org/show_bug.cgi?id=24952
--- Comment #2 from Mity mity@morous.org 2010-11-15 14:29:36 CST --- Thanks André. Your commit e054fc23100f347ae3ed026d24f183aa85b8c802 fixed the issue. With Wine 1.3.7 the mCtrl split button emulation works as intended.
I'm not sure what's the policy about resolving issues here, so I keep it open as I'm just a visitor ;-)