Car Alarms: trouble with Viper alarm, celica gt, toyota dealership

Question
My son just bought a 90 Celica GT with a viper alarm. We got it home ok and today when he went to disarm it, you could hear the actuator unlock the car, but the door wouldn't open. He used his key to open it and the alarm went off. Now this evening, my husband went out to turn off the alarm so he would only be able to open the doors with the key. He put the key in the ignition and turned it to the on position, then pushed the button to disarm the alarm. Every time he did this, the alarm would go off. He got out and shut the door. Now, we can arm and disarm the alarm with the key fob, but the actual key will not unlock the car. What do we do? We now have a car we can't get into.  

Answer
This sounds mechanical in nature.
I believe the locking system is malfuntioning
here. If possible, have this towed to the
nearest Toyota dealership for inspection.

If it was electronic, that's one thing, it
appears though that the lockout is mechanical

Good luck with it.

ALARMTEK