I have an Accenta 8 Mini Alarm, Tamper Indicator On?

I have an Accenta 8 Mini Alarm, just recently the alarm has started to go off (both sounder and strobe) of its on accord even though the alarm has not been set. If it normally goes off like this its due interuption in power supply but this has not been the case of late. When we enter our code the alarm stops but the Tamper Indicator lights remains on until we reset in which case it does go off. This has happened now three or four times and before i get an alarm engineer involved does anyone have a clue to what the prob could be?? Thanks