I recently purchased a 1995 E330D with 120k on it. Very nice car and drives beautifully. One idiosyncrasy it has is that frequently, but not always, the doors will lock on exiting the car without the use of the key. All the door buttons will depress, but after a moment, the driver's side will come part way back up, though the door will remain locked. When the doors like this way, the dashboard alarm light will not blink, as it does when I lock the car with the key.

An alternative, related problem is that sometimes I will lock the car and come back later to find the drivers side door open.

Any thoughts or ideas on how I might resolve this? Is this a vacuum issue?

Thanks much!
Tom G