HELP! MY MONDY LOCKS MYSTIFY ME!

I've just had the MOT done on my 03 TDCi.

When I got it home and used the remote-locking, the usual 2-flashes of the indicators did not occur.
So I checked all the doors and tailgate were shut.
I undid all the seatbelts that had been left closed.
I had deliberately only left the garage the one remote key
(had a similar problem before when I left the plain key and then used the remote to drive away.)

What have they done?
How do I reset things?
Many Thanks

eljay