i also had a good experience with nokia uk customer care my n900 usb charging port came out of my first model. went online filled in the form and posted it off about a week later i had a new n900 sent to me was very happy haven't had any problems with the new phone and has outlasted my original one by some months now

on a side note i would recommend using some pliers and pushing down the little prongs that poke out of the bottom of the charger cable this makes it far easier to slide the cable in and out