iPod touch Ever had this problem with your Touch?

I've had mine for the past three weeks and every once in a while the main menu just stops reading my fingers. I can lock, unlock and reset the iPod every time which always fixes the problem.

I don't know if it has to do with the altitude or colder weather (around 30 farenheit but inside of my coat pocket most of the time), but it's starting to worry me a bit.