[H] Vista DUN won't work

[Thane Sherrington]

I have a brand new Toshiba with Vista in the shop, and I'm trying to 
setup dial up networking.  It dials fine, the modems handshake, it 
starts the username authentication, and then it disconnects.  It 
gives the message "Error 1717: the interface is unknown."  I can't 
find a resolution.  Anyone see this and have a suggestion?  The 
username/password works with XP.

T