I am experiencing the following symptom with both of my remote key fobs.
The symptom is that all buttons are unresponsive regarding locking or unlocking the vehicle until I point the remote fob directly in front of and close to the front windscreen.
I have changed both fob batteries (which were not faulty or "low") and the symptom persists.
I have heard that certain external electrical devices or those that are in close proximity either inside or outside the vehicle can interfere with the signal.

Has anyone else experienced this?

 

There is a DIY In he How To Section by Jon89 that explains how to take apart the FOB and clean all the contacts.

Try this free fix first.

 

Thank you for your suggestion regarding switch cleaning. However and what is curious is that all eight fob switches function perfectly well when used just in front of the windscreen and when I move a few feet away none of the eight switches function. This is a repeatable and constant condition. So this makes me consider that it could be a signal issue - in other words interference from another device or the remote receiver in the vehicle may be the culprit.

Update 19/05/2016 - 17:40

Well - rather embarrassingly I have identified the cause of this.
Some time ago I installed an interior mirror with built in camera and integral 3.5" screen. The unit also included a rear view camera which I mounted to the headlining above the rear screen. At the time of fitting I didn't have a permanent live feed to the unit (just used a USB converter in the cigar lighter socket that is only powered when the ignition is on) which meant after a while of not using the car the camera/recorder battery would run flat and reset the unit to factory defaults including the date. So just recently I installed a DC to DC converter with USB 5vdc 3amp output connected to a constant live from the Primary Fuse Box. This allowed the camera unit to remain powered and not loose date/time etc. This was a good solution as the camera unit would fire up when I unlocked the car and immediately go into record mode.
You can see what I'm doing here can't you - I'm trying to justify the fact that I caused the remote key fob signal to be interrupted by the extraneous signal swamping that was being emitted from the camera unit when constantly powered.
Anyhoo I disabled and removed the mirror cam and both key fobs are working correctly. So I'm faced now with how I can use my mirror cam (which is an excellent piece of kit - yes it's Chinese but it works really well) without affecting my key fobs.

The mirror cam is reviewed on You Tube -

 

Bobs your Uncle wtg.