XM is facing problems with the FCC in regards to some of its portable XM tuners that ship with regular FM modulators. The devices from XM have been said to not meet radio device requirements set by the FCC that all consumer FM transmitters must meet. Many XM radios rebroadcast the XM feed over a low FM station so that inexpensive FM radios can play the audio stream.
Problems are following XM around like the plague lately. If you were considering purchasing one of these radios, you may just want to hold off. Check out the full posting at DailyTech.