Remote Locking Problems

[a2z]

We have recenly started having trouble locking/unlocking our ONE (2005) with the remote key. It has been sporadic for the last few weeks but in the last few days you have had to stand right by the car and press the button several times for it to work. Sometimes we have just given up and used the key proper. Poking around on other forums there seems to be an issue with radio interference from mobile masts etc (don't think anything new has been erected recently nearby and we don't live near an airport/police station), also, it happens mostly outside the house but also sometimes in other places. I have also read that some owners are coming back to unlocked cars that they are sure they locked and sometimes the windows/sunroof are open!

Anyone else had this? What do you think the likely solution is? (is it a dealer recall for example?)

[a2z]

The new keys charge from the ignition barrel. We rotate the keys occasionaly to keep them both charged (they are only 6 months old)