OK Mike this is not going to help. But the meter reading the camera is giving you is probably a spot meter from the centre of the frame so if you where to move your camera round the scene then the meter reading would change. So I guess you are metering from a spot with your cameras and a different spot with the hand held meter. As a point of interest my camera has spot, centre weighted and zone metering and I get a difference of 2 or 3 stops some times. Just to add to all this the right exposure is down to you and what you want to achieve in the picture, so there is no right exposure just an average one which is what the camera is trying to give you. If it was me I would look at the readings make a call on the scene light /dark and go for the appropriate reading I told you this would not help. :)

Those who do not want to imitate anything, produce nothing. Salvador Dali