The 4 door locks of my 2008 Sebring will unlock with either the key fob or door switch, but neither makes them lock. With the key fob, they unlock and the horn beeps. With the door switch, they lock, but unlock again real fast--sort of a double lock/unlock.

After manually locking all 4 doors, with the key fob, they will quickly unlock/relock/unlock. Sometimes the headlights come on while other times the horn beeps. It is a variable combination, but the bottom line is this: they never stay locked using the key fob or door switch.

Any one have any ideas or similar problems?

 

Sounds like the car thinks the key is in the ignition. It's designed to make it more difficult to lock the keys in the car. There's a little switch in the ignition that senses the presence of the key. Maybe that's stuck. Try a drop of WD-40 on the key to see if that will free it up.