There are also micro-switches that fail that cause it to not drop at all (handle switch) or go back up while the door is open and the handle released (latch switch).
Whatever the problem, look through these articles at Pelican:
Porsche Boxster Door Lock Mechanism / Door Handle - 986 / 987 (1997-08) - Pelican Parts Technical Article
Porsche Boxster Door Panel Removal / Mirror Switch Replacement - 986 / 987 (1997-08) - Pelican Parts Technical Article