Basically this is bug 6971 (http://bugs.winehq.org/show_bug.cgi?id=6971). X doesn't offer relative mouse movements this means that we don't receive events when you reach the borders of a window and then the mouse can escape the screen (we fake the mouse cursor I believe). The hack lets us recenter the mouse cursor this fix some programs but it breaks lots of others. The issue can be fixed soon when Xorg will ship Xinput 1.2 which does offer us relative mouse movements.
