Using Ibook g4 and Tmobile razr

I'm currently trying to use my tmobile motorola razr phone as my modem by bluetooth. I have tried every tutorial there is online and it looks like I almost have it. I'm receiving an error message now that says:

could not negotiate a connection with the remote ppp server. please check your settings and try again.

I've already searched these boards for any help and have not been able to come up with any solutions. Any advice would be appreciated. I followed this tutorial.

http://alpharuin.blogspot.com/