Hi Alan,

I've encountered that problem on a pair of 306s.  The problem with
them both started like that and moved on to intermittent failures of
the remote part of central locking.  One other  symtom was water
appearing from the roof console when cornering - and no that's not the
sunroof gulley drains being blocked.

The problem was due to water getting in through the roof mounted
aerial and collecting in the bucket shaped part of the roof mounted
centre console.  Here's how to check.  Pull off the back section of
the roof mounted centre console, lift the back edge gently and it'll
come off in your hands.  Unscrew the two screws and the whole console
will drop about an inch.  check for signs of water present or the
dried remains.  The IR sensors are in the little box at the rear of
the main printed circuit board.  You may need to move the cables
around, and then ease the small board out.  On it's underside are 3 or
4 IR detectors, they should be clean and black, if there are grey
deposits then that's why they can't see the light from your key fob.
Clean and replace.  Also clean out the bottom of the area that  you
ust remved them from.

Oh yes, and refit the aerial with a smear of sealant to stop it
happening again.

Enoy,

Derek