This may be the same problem I encountered with kubuntu 6.06. I was getting the message "pppd died The remote system is required to authenticate itself" when kppp was run from a terminal. I read the kppp help and I found a section where they suggests to edit the /etc/ppp/options file or to simply remove it. I removed it and kppp successfully worked.
-- kppp will not connect using phone as modem https://launchpad.net/bugs/13694 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs