Okay, so with a little more research, I have found a reference to the problem in this thread over in HowardForums...

http://www.howardforums.com/showthre...hreadid=998021

"- Edit /etc/ppp/option and uncomment "+pap" and "-chap". It appears that vzw can't handle the attempt at CHAP authentication."

I recall that I did have to do this on my MacBookPro to get it to work with bluetooth DUN as well.

Now my question is, how do I get at "/etc/ppp/option" in order to make the edits required?