https://bugs.winehq.org/show_bug.cgi?id=34594
--- Comment #14 from Dmitry Timoshkov dmitry@baikal.ru --- (In reply to Dmitry Timoshkov from comment #12)
Chessmaster's menu implementation depends on WM_WINDOWPOSCHANGED message sent to (a being deactivated) menu window when one clicks on the main window.
It's a WM_WINDOWPOSCHANGING message actually.