Security Alarm System Life Expectancy

[T.H.E. Binz]

I haven't seen a thread on security systems in a few years, but am I the only one having problems with their alarm system? My system is about 7 years old and only consists of two hard-wired motion detectors and two wireless motion detectors. When the batteries die in the wireless detectors it sets off the alarm and subsequent visit from the local police (Meredith in this case). Now the hard-wired detectors are going bonkers. Two service visits by the alarm company have not fixed the problem. The police have been marvelous and very patient with this situation, but I'm wondering - is this a matter of equipment life expectancy, i.e., time to get a new system?