|Project:||The Open Toolkit library|
This is likely a symptom of one of the previous support tickets, but I didn't find anything that quite described the issue, so here goes nothing...
When the user clicks the mouse within the window, drags to a point outside the window, and then releases the mouse, no MouseUp event will be delivered, and the MouseDevice will firmly believe that the mouse button is still down.
Perhaps needless to say, this makes any kind of mouse-driven camera manipulation extremely unpleasant/unworkable. Equally, while the in-progress mouse capture functionality will allow one to work around this bug, I think it is still a bug: most standard Windows controls (i.e. buttons) respond to MouseUp events outside of their frame.