http://bugs.winehq.org/show_bug.cgi?id=31979
--- Comment #18 from Daniel Santos daniel.santos@pobox.com 2012-10-15 14:47:29 CDT --- Wow! what a busy bug!
So I have some time right now so I'll debug it, but I'm having some problems with winedbg at the moment moment, so I'll have to troubleshoot that first. Building current git wine first as well and then going to try this patch submitted on the appdb page:
--- wine-1.5.10.orig/dlls/user32/winpos.c 2012-07-31 21:08:12.000000000 +0200 +++ wine-1.5.10/dlls/user32/winpos.c 2012-09-01 14:43:47.000000000 +0200 @@ -251,8 +251,7 @@ BOOL WINAPI ClientToScreen( HWND hwnd, L */ BOOL WINAPI ScreenToClient( HWND hwnd, LPPOINT lppnt ) { - MapWindowPoints( 0, hwnd, lppnt, 1 ); - return TRUE; + return MapWindowPoints( 0, hwnd, lppnt, 1 ) != 0; }