Neck pain on a road bike?

       One of the guys I work with got a Treck OCLV this summer.  I haven't seen him on it but judging from his size, he's 5'8'' with more the short leg/long torso type of body, size 52 sounds right to me.  Now that his rides are approaching 40 miles he is experiencing neck pain while riding.  I've heard that this is a position problem, but don't know the cause.  Can anyone help him with this?  What do you think is causing the pain in the neck?