I'm getting slightly confused towards the end of your message. You say that after you corrected the problem, then 2 weeks later the alarm's door unlock feature stopped to work. I translate from then on as follows: The power locks lock when: the car is armed (alarm activated), the car is started, and when the standard door lock switch is used. Now, The doors do not unlock when: the alarm is disarmed, the car is shut off, or the standard power door lock switch is used. Hmmm, retyping helps mre remember.

I've played around with my Integra's Alpine alarm and I've got an actual Integra manual (the real mechanic's version) along with an electrical troubleshooting manual. I'll look in the troubleshooting manual for you - I'm betting your 2000 Civic is wired the same as my 96 Integra. I'll let you know what I find out, but right now I've got a strong hunch I know what the problem is. I'm not certain, but I believe that there are 3 wires running to the switch. Odds are, the wire that unlocks the doors is loose or fell off.... but I have to verify this....

I'll let you know.