Close LaunchBox, then navigate to \\LaunchBox\Data\Settings.xml and open that up in a text editor. Look for a "<EnableGamepad>true</EnableGamepad>" (without quotes) and then change true to false. Save the file and close it, then reopen LaunchBox. Mouse should stop doing that. Sounds like you have controllers enabled and the "Use all controllers" checked and you have a device that is sending a signal. This happens a lot with some peripherals like wheels.