There are probably many ways for this to happen: changing monitors (unplugging one monitor and plugging in another), changing display settings, accessing your work machine through remote desktop after using SlickEdit on your work machine, and even a laptop going to sleep and waking up (this is more rare). The most common is the remote desktop case. I would get this when I remote desktop into my work computer from home. As much as we like Qt, there are some issues we have not been able to work around and this is one of them.