Range Rover P38 Imobilser Problem

I have just had the battery replaced on my RR, before this the interior light did not work when unlocking the vehicle and the indicators flashed as normal, after the battery was fitted the interior light now works but the indicators do not flash when locking or unlocking, instead the side lights do this, also in the middle of the night the alarms go off, I reset it but when I get up in the morning the side lights are on.
The vehicle is a 1998 2.5 td with 53,000 on the clock.
Any body help?:welcome2:
Regards Martin.