What I was talking about on the headrest is the plastic lock for the headrest. If it brakes then the headrest will go up because it is being pushed, but when going down only the system or lock will go down. It is supposed to pull the headrest back. I've changed many of these because people try to remove the headrest without pressing the "hidden" release button on back panel of seat. The part that has to be changed is the track with the small box, which is the lock and release mechanism for the headrest.
The only reason why I know that this is your problem and not the switch is because you said that you have to push the headrest back. Here is a simple test: raise the headrest all the way. Now try to push it back, gently of course. You shouldn't be able to push it back. Now lower it a little with the switch. This time you should be able to push headrest down until it hits the lock release box.
Also, you should be able to pull out headrest without releasing it. Try it out.
[Edited by vinamg on 04-13-2001 at 11:00 PM]