This is in the episode where an ex-con friend of Lamont's comes looking for a job. When Grady finds out out he's a felon, he hides the radio in the freezer to keep him from stealing it. In the middle of the episode, he remembers and goes to retrieve it, but it's frozen and covered in ice. Grady tells the ex-con to go steal him one, but when the man comes back like an hour later, the radio is still covered in ice. In fact, at the end of the episode which is suppose to be the next day, you can see the radio in the background still covered in ice.