The exact same thing is hapening to my car right now (96 328).
I think the actuator is going. I am too cheap to replace it right now so I'm just using the key instead of the remote.
<img src='http://www.geocities.com/royb9t8/MY_BMW_2.jpg' border='0' alt='user posted image' />
<span style='color:blue'>My ass may be dumb, but I ain't no dumb ass!</span>