Here is an update of what I have discovered by trying different viewers. Hopefully someone with tech knowledge can put this to use to help others with the line problem.
First, Treat, I tried your suggestion with the GL vertex buffer in the SL3 viewer and it did not change anything.
I have installed 3 viewers...SL3, Phoenix and Firestorm. The SL and Firestorm viewers both show the line around the neck. The Phoenix viewer is the only one that does not show the line. Maybe if someone knows what SL3 and Firestorm viewers have in common that the Phoenix one does not then maybe there is an answer to this ongoing problems for people.