I know old automatic car antennas have a tendency to not go up and down properly all the time, but what is the usual problem causing this? I've only had mine working one day for the first time since I've owned the car (just got the radio replaced yesterday) and I'm already having problems with it not "descending" all the way down. A couple of the sections seem to not want to collapse and go down. So what is probably my problem? As always, thank you in advance for the helpful replies, Richard