Help !!! Key fob won't work !!

I have a 2005 Disco 3, can anyone advise me please !!
the key fob will not lock or un-lock the car , starts and drives fine ,
when pushing the buttons on fob to operate nothing happends, tried the spare key and it's the same !
but when locking and un-locking with the buttons on the dash all doors lock and un-lock !!
this seems to happen all of a sudden when the cold weather hit us !!!!!

Thanks
Tony

Hi, this is my first posting and I have just purchased a 2004 disco 3 and have encountered the same problem,so i removed the plastic panel inside the passenger footwell found the small plastic joint with 3 green and whites wires in, re joined them with a heatshrink joiner and now key fobs are back running. Repaired in about half an hour.