I looked over the specs on the Raleigh and it seems like it has some good parts hung on it.
Handlebar: Easton EA50 31.8 Stem: Easton EA30 31.8Headset: Ahead 1-1/8As the others have said, check the cap and then the torque of the stem bolts and see if they are good. Could be a stripped stem bolt, but the Easton Stems are pretty darn good.