I had exactly the same problem, but in Mandrake. My directories will probably be different than yours (hopefully not the commands), and here is what I did(please mind the typos):
# cd /usr/sbin (or wherever your firestarter bin is)
# vim firekiller
Hit [Esc] then [i] to insert the following(note the backward '):
kill -HUP `ps -C firestarter -o pid =`
Now, hit [Esc] then [Z] then [Z] to save. Now,
# chmod +x firekiller
which creates a script to kill firestarter after hanging up on kppd.
Assuming you have the SUDO command and its config file sudoers is in /etc...
# cd /etc
Hit [Esc] then [i] to include the following lines in the file:
#User Alias specification
User_Alias FIREUSERS = yourusernamehere1, username2here
#Cmnd Alias specification
Cmnd_Alias FIRESTART = /usr/sbin/firestarter -start
Cmnd_Alias FIREKILL = /usr/sbin/firekiller
FIREUSERS ALL = NOPASSWD: FIRESTART, FIREKILL
Hit [Esc] then [Z] then [Z] to save. If there is a typo, follow
its instructions and correct it. Try visudo again if unsure.
The NOPASSWD lets FIREUSERS group users execute only
FIRESTART and FIREKILL without a password.
In kppp, configure your execute settings in your dialing
(I dont know the exact titles, but the order is right.)
[When Connected]: sudo /usr/sbin/firestarter -start
[After Disconnect]: sudo /usr/sbin/firekiller
Save your profile, and give it a shot. Let me know if you run into problems. Keep in mind, I'm a newbie myself, and have only been on Linux about a week now...j.p.b.
Any Xperienced Linux gurus out there let me know if ive goofed..