door light permently on, alarm not working on my rover 620ti?

on the dashboard there is a safety light to insure all doors are closed, this is permanetly lit up, and i have slammed the doors time and again, also at the same time as this started, my alarm started to go off for no reason, and now it wont activate. The central locking still works on the key fob, and these two are linked in some way. Please help!