I've never used Kppp, but I guess that
you're half-way there ... what you did
was give the user and group who own
options the rights to read/write and
If you do a
ls -l /etc/ppp/options
which user/group do you get as owners?
You'll need to be member of that group
to be actually able to use it.
The alternative method would be to start
pppd as a demon with deman-dialing
enabled ... that way the normal user won't
have to bother with kppp, but instead, as
soon as he tries to access any net-ressource,
pppd will (try to) establish a connection.