Driver's side power-lock actuator makes noise but wont lock or unlock with remote!

[aSadSaaber]

My girlfriend picked up a 1999 Saab 9-3 SE 2.0t 4 dr auto with 170k in November.
Thanks largely to this forum I've been able to keep it puttering along whilst being a lurker but now I have been drawn out of the shadows by this problem with the locks.

The car has an aftermarket remote starter that had been installed by the PO. When we bought it the PO said that the remote start had stopped working, the trunk release button had never worked, but the lock/unlock worked fine.
When the unlock button was pressed it'd unlock the driver's side and then about a second later all the other doors would unlock.

Last week I tried to lock the car when I noticed it sounded like the lock actuator was fluttering and failed to engage. I unlocked and locked it a few times and then it engaged.

Then it started to have problems during unlocking as well, both problems becoming more frequent until, finally, nothing happens when the remote is pressed.

So now she is using the key to lock/unlock the doors but it's sometimes hard to turn the key and it still makes the sound of a fluttering actuator. The lock also flutters when the lock/unlock buttons on the center console are used, but the other three doors lock normally. I know nothing about how the stock Saab central locking works or how the installation of this aftermarket remote was performed so I'm having a dickens of a time trying to figure out where to even begin addressing this problem.

(And of course) She's about to start a new job in a somewhat questionable area and I'm worried about something happening to her because she can't get into her car fast enough.

I think I'm going to start by taking off the door panel to take a look, but since I'm so unfamiliar with Saabs, finding the source of this issue between the factory central locking and/or aftermarket remote starter (in such a short time-frame no less) is something that I'm not confident I can do by myself. Please help me Saab enthusiasts, you're my only hope!

Sorry for the long post but I wanted to make sure to include any details that may be relevant. Thanks so much in advance you guys are awesome!

[dgroet]

My '02 does the same thing. i think it's the actuator, but not 100% sure.