MY 406 locks went awfual after some snow: very intermittent remote locking and pretty dodgy with the key. I thought that taking the locks out and dousing them with oil would sort it all out: Wrong! The key worked fine but still no remote. Tried all the resetting tricks (didn't go as far as disconnecting the battery, I admit), changed the battery in the key but to no avail. Then the remote key was lost for a fortnight, and when it was found again it worked perfectly. So try chucking the key down the back of the sofa for a fortnight and using the spare. Failing that, stop trying to push the remote button for a while.
Dave, Hastings, March 2011