How do can i get the tamper light off my Veritas R8plus alarm?

Hi,
I've recently moved into a new house and the internal alarm has just gone off for No apparant reason with the Tamper light and the green light flashing on the key pad and the green light flashing on the mains box. No zone lights were flashing. When i tried to disable it the alarm code given would not work. I tried to type it in several times but to no prevail, so i pulled one of the fuses out of the mains box which triggered the external alarm. I quickly put the fuse back in and typed in the code which de-activated both the internal and external alarms but the tamper light and the green light are still lit on the keypad although, the noise has stopped. We do not use the alarm so aren't bothered about it using it but i don't want the alarm to go off again as it's late. Do you have any suggestions? The only thing i can think of that could of had any influence is that i turned off the mains power earlier in the day as i was replacing some light switches and sockets, but this was only for about 30 mins and then i switched it back on with no problem until now. If it goes off again how do i turn it off quickly.

Thanks