http://bugs.winehq.org/show_bug.cgi?id=15346
--- Comment #26 from Peter Dons Tychsen donpedro@tdcadsl.dk 2009-10-07 19:44:19 --- There is a bug in the X11 mouse code which is affecting this problem. The mouse code is using the cached values "whole_rect" and "client_rect". These are not updated at the correct time, so the calculations end up bad. This causes the "jumping around" that you are seeing.