There is a thread that I started awhile back about alarm problems. Some folks had suggestions about a failed driver's side door lock which you might find interesting and helpful. MY alarm used to go off when I UNLOCKED the driver's side door. No effect when opening the other doors or the trunk. I decided not to try to further diagnose the problem and simply disconnected the horn portion of the alarm (at the horn itself under the hood on top of the driver's side wheelwell). The lights still flash when the problem crops up, but I just relock and unlock again to stop that little annoyance. Sounds like you do the same kind of thing. I will take a look at unplugging the control unit and maybe someday look to find out the true problem and correct it.
My 1st wife just called to try to determine if she could extract more $$$, so I don't think I'll be doing many really expensive things for a little while. But I'm about to rant so I'd better get off ....
2003 Dodge Durango SLT
2002 BMW E39 530i Sport
1988 Mercedes 300TE
2003 Chevrolet Suburban