3902t on 07 silverado problems.

So I have been searching for days. I installed a 3902t OEM intergration alarm in my 2007 NBS silverado. I added glass break and tilt sensor and everything works except my factory remote start and the factory horn still goes off when arming, if you open the door the factory horn will sound but not the 514n Siren. If the glass break or the shock sensor go off the siren will sound with no horn. It's like the 2 systems are not working in conjuction with each other. I updated the firmware to 5.0 and still have the problem. If I reset the factory ECU and clear the DTC's then I can remote start again until the sequence is messed up (press the arm button once, arm the 3902t and not the factory alarm) then you have to clear the DTC's again. Anyone have any ideas?? I half tempted to rip it out and do a 5702p with a DLPK. If I were to do that would the DLPK handle the remote start since it was a factory installed option?

I do not know about the 07s, but if you put an alarm on an 02, and someone locks the doors with the door switch, that activates the factory alarm.  If you use the aftermarket alarm to disarm and unlock the doors, when you open the door, the factory alarm WILL be set off.