That's interesting. I have just been told the same thing at Dramensveien Service Centre (OSLO)... but your post is from April '14!
My problem is different: the remote control button does not work anymore. You press, but the charge port doesn't open. While I was on holidays in Belgium I had this checked at their Service Centre in Brussels, and they said the UMC needed replacement. In fact, they offered a new UMC, which I refused explaining the Norwegian grid is different from Europe and I needed a specific UMC.
So back in Norway I contacted the Service Centre, and they've told me that they could replace it but prefer to wait because the remote control is a known issue and Tesla is working on a new UMC. They said that once the new UMC is ready they will recall all existing UMCs...
Anyone else has had this problem with the UMC remote not working?