RS problem or Not

Installed an ultrastart 1250 on an 94 accord a while back.  Today customer calls me and says his car doesn't work, he can't drive it.  went to go check it out.

Heres what i noticed. 

1. the RS works fine.  I get in the car, turn the key to IGN, press the break BUT the car shuts down. 

2. start the car with the key, won't stay started, i have to keep the key in the RUN position, in order for it to remain started.

3. if i put the key to ACC, no lights turn on, if i put the key to IGN, no lights turn on. its as if the key cylinder is not seeing ACC or IGN. it was pretty damn cold so i didn't have a chance to check the fuses.

can this be due to the installation of the RS. or another random event.

4. so in order for customer to drive the car to my garage he has to remote start the vehicle, put the key to the RUN position and keep it there, while driving. 

will this damage the car?

and whats wrong with the key cylinder

By RUN position, do you mean CRANK with the starter still turning?  If so, I wouldn't recommend driving very long like that.  You could damage the starter, flywheel, or both. 

Sounds like the IGN is not powering up by the key.  Check wiring and plugs associated with ignition wiring harness, maybe something got pulled on during the install and finally loosened up.  Check for power on wiring accordingly.  If remote start still works and wiring checks OK, its possible the ignition switch failed.  If thats the case, sounds like a billable service call.