When I use kppp, pppd quits with exit status 1, which the manpage says means a critical system error was encountered. The pppd log:
Mar 26 18:01:31 debian pppd[797]: pppd 2.3.11 started by norm, uid 1000 Mar 26 18:01:31 debian pppd[797]: Using interface ppp0 Mar 26 18:01:31 debian pppd[797]: Connect: ppp0 <--> /dev/ttyLT0 Mar 26 18:01:31 debian pppd[797]: Warning - secret file /etc/ppp/pap-secrets has world and/or group access Mar 26 18:01:34 debian pppd[797]: local IP address 216.17.10.8 Mar 26 18:01:34 debian pppd[797]: remote IP address 216.17.3.207 Mar 26 18:01:34 debian pppd[797]: primary DNS address 216.17.3.121 Mar 26 18:01:34 debian pppd[797]: secondary DNS address 216.17.3.122 Mar 26 18:15:28 debian pppd[797]: Terminating on signal 15. Mar 26 18:15:28 debian pppd[797]: Connection terminated. Mar 26 18:15:28 debian pppd[797]: Connect time 14.0 minutes. Mar 26 18:15:28 debian pppd[797]: Sent 68030 bytes, received 279237 bytes. Mar 26 18:15:28 debian pppd[797]: Exit. wvdial, on the other hand, works fine, and so did kppp before a reinstall of my computer. I'm thinking authentication is part of the problem. On terminal-based authentication, pppd doesn't crash until I click 'continue.' The kppp setup forces some type of authentication option, but the wvdial pppd config file has the noauth. I can't add noauth to "Additional pppd arguments..." under the kppp setup because it contradicts with what kppp automatically sends. Any suggestions would be much appreciated. Thanks!

