http://bugs.winehq.org/show_bug.cgi?id=18899
--- Comment #5 from Nikolay Sivov bunglehead@gmail.com 2011-05-12 12:41:58 CDT --- Interesting, tab control gets WM_LBUTTONDOWN instead of WM_RBUTTONDOWN (and not *UP one, that is not so interesting).
Will take a look at their code.