It's not clear from the video whether the mIRC channel window is being minimized or if the window inside it, ie. the listbox, is being minimized. Either way, I cannot think of any reason why this would happen. A window in mIRC should only be hidden/minimized if it is sent a hide/minimize message by another application. The fact that it does not affect other applications does not indicate an issue with mIRC, it just means that the driver has not been designed to handle the combination of Windows that mIRC has. I've heard of similar issues with mouse/pad drivers over the years and the solution was usually to update the latest driver or to report the issue to the manufacturer.