Don't know what the window problem is but I had a similar situation to you with the arial.
When it happened to me the stereo switched off as well. I eventually traced the problem to the removable (face off ) buttons panel on the front of the stereo. It was not quite seated properly. I just took it off & put it back on again & it's been ok since. So simple but it took a while to find it ! I reckon regular pressure on the power button gradually dislodged the panel.
Might be your problem too - give it a try!