Its driving me mad !!!!?

Try this :-
prog 9 9 9 9 3 (if lamp 3 is on at this stage press 3 to turn it off) reset reset.
now try arming and then disarming the system with your normal code.
If you get alarm at power cut it suggests your back up battery is kaput, if its over 5 years old, replace it anyway as they dont last for ever and a dead battery can cause false alarms and could also render the main circuit board totally u.s. under certain conditions. A new battery is less than £10 (screwfix direct have them)

Pete
May 2007