I have a problem with my Melcom ST6100 alarm control panel?

I have recently installed a melcom ST6100 alram control panel, however whe I attach the alarm box the tamper light remains on so will not let me set. There is no tamper fault as the lights on the alarm box signal correctly, if I press the panic alarm it all works ok. But because the tamper alarm is always on I can't do anything, any ideas?