I saw online, a news brief from nissan, saying they are having problems with the key codes becomming disabled if the key gets to0 near your cell phone.
It appears to be happening on some 2007 g35,s, and altima. Letters will be sent out.
They are advising you keep your cell phone and key at least an inch apart.
Anyone with an x, having this problem?

Stay safe

Reuters Article

There's only one way to find out. Definately will keep the phone away from the key when on trips ect.

I don't think you have to worry too much about it. It is for the keyless starts, like the Murano and Altima have. My keys and phone live together in my desk draw for about 9 to 10 hours a day 5 days a week for the last year and half and my X starts right up every time.