[sb01box]

let me be the first to chime in. I went down this road just a month ago - not exactly the same road and also note that this is a very green mechanic's recollection of 2001 boxster - - - so beware there may be lots of bad information.

You did not specify whether the problem is only with the inside handle, outside or both.
During my tear down of the door mechanism i found that the opening of the door is initiated by releasing a spring loaded latch within the door mechanism and this release is via all mechanical connection. The end to end mechanical connection does includes a motor driven worm gear piece which acts as lock/unlock link. if this motor/worm gear is broken and is sitting in the locked position, both inside/outside door handles have no effect. the door will not open, the window will not drop - but if this is the case, the alarm system should see an error and light up the LED on the lock/unlock button. is your car behaving so?
if the mechanism is fully connected and you can hear the motor when you push the lock button, then maybe a spring in the latch mechanism is broken so that the latch does not spring free. Under this condition, I can envison the alarm system thinking that all is OK but that the door is jammed shut by something preventing it from opening. but the window should roll down.
you may have the same problem that I had, which was bad solder of the connector leads in the printed wiring board inside the door mechanism.
I had the battery connected during my door panel removal (with the airbag looking directly at my face) and when i tried to remove the harness, the window started acting up. I took the door mechanism off and resoldered the joints.

good luck
Tad