Which radio was it, this one http://www3.towerhobbies.com/cgi-bin...adio&search=Go ?

I wouldn't mess with trying anything, just send it back and let them take a look. If it is indeed defective, they'll either repair it or more than likely, replace it. I would enclose a note and ask for a different channel though if they replace it in case that was the root of the problem.