alarm going haywire

hi, my sister called me about a problem with her 95 prelude and i have no idea what to make of it. yesterday she got her brake rotors and master cylinder replaced and drove the car home. today, she says she unlocked/disarmed the car and then tried to start the car but it just beeped or something and didn't crank or anything. then she got out and tried to engage the alarm and it beeps once when it normally beeps twice to arm the alarm, and the doors don't lock. i have no experience with alarms so i have no idea what this all means. anyone have an idea?

oh, btw the alarm is a hornet 740t or something like that and its been installed for 4 months with no problem.

Bring it back to where is was install. 4 months old mean they will and should warranty their work. Don't touch anything or else you are the scape goat. It may just be a simple programing procedure that needs to done. Be careful whose advice you buy, but be patient with those who supply it.