Paul,
The following may not be the news you want but it may help!
I have an 08 Freelander 2 from new. About 6 months after purchase I had the same problems you describe. My dealer in Ripon was very helpfull and sympathetic, but could not find the problem. Over the following nine months they had the vehicle in four times. Sometimes the fault lasted a second, we only knew when the sat nav lost its route or the CD returned to the start of a track. Other times it locked until we turned the ignition off and back on.
Eventually my dealer said they could do no more as Land Rover did not understand the problem and they had never seen it happen. Being a bit stubborn and with a dose of luck I set up a video camera and waited. The following day, while driving in Lancashire, the sat nav jumped to Germany and a few moments later announced " Welcome to Great Britain". Armed with a DVD I returned to my dealer, who sent it to Land Rover, who gave me a new sat nav.
I suggest you keep a record of every time the fault occurs and keep in touch with your dealer.
Mapster