Yesterday I pulled into my driveway, and I had the stereo on. Usually when I turn the ignition key off the stereo stays on until I open the door. But yesterday the stereo went off, the horn started blowing, and the doors wouldn't open, this all happened as soon as I turned the key off. I could only open the doors manually. I tried 3 or 4 times to get things working but they wouldn't. I let it sit for about 20 minutes, tried it and everything was ok. I was wondering if this is anything to worry about.