There is always confusion regarding UK v US cars. The info is only in the US
manuals. Also, the procedure to make a new key start the car by realigning
the PAT function is in *both* manuals, so further muddying the waters!

As I'm sure you are aware by now, to make a new key start the car you need
to have at least two existing keys.

There are apparently two remote systems in use. The procedure below is for
Siemens keys. I've not seen others, but apparently they exist.

Sit in the car with the doors shut. Turn the remote key from fully off to
ignition on, (but not to the cranking position) four times. The door
open/lights on chime will bong once. Press the door open button on the fob.
Complete this procedure within 10 seconds. This should align the radio
function of the system.

I had exactly the same problem as you with my '99 LX. After the above
procedure, the remote function of the key still didn't work, so I assumed
the key was broken.

I needed a CR2032 battery for a remote door bell, so robbed the one from my
key fob. Some weeks later I was scrapping a computer motherboard and
realised it had the same battery; I put the battery in my keyfob on a whim.

Lo and behold! The remote function now works! Don't ask for an explanation;
I don't have one.

That was over a year ago; it still works fine. If all else fails I would try
leaving the battery out for progressively longer periods of time.

BTW, all the above information has been posted in this NG a number of times,
and could have been found using the search function in Google Groups. This
might save you time in the future.

HTH

Chris