I have this issue, in 4.12.3, where when left alone, minimized, or just not the active window, limewire freezes up when downloading. When swapping back to the application, the window comes back blank, and the app needs to be killed from task manager to close it. This was fixed TEMPORARILY only by Lord of the Rings suggestion to delete the LW preferences. It worked for a couple of days with no problem, then the behavior returned..