I recently experienced the mystery flat problem on my front tire. About every other week the thing would slowly go down during a ride. I got really good at changing tubes out on the road (I'm thinking about joining a Nascar pit crew). Sometimes it would just go down overnight. I was to the point of just buying a new tire one day and I decided to inspect the inside of it one more time and found a very small pice of wire. Going on a month now and no flats.