This might help both of you guys.
Mitch99 is right, you need to do a modprobe for them both as root in a terminal:
modprobe ppp_generic
modprobe ppp_async
insmod ppp_generic
insmod ppp_async
Also, you might want to try to run X with KDE and open up Kppp. This will allow you enter all your pertinant information (domain name, primary/secondary DNS, phone number to dial, PAP/CHAP authentication, user name, password, etc.). When you're done, you can just click on dial to connect. If you dislike KDE or find another window manager/desktop environment you like better, you can change your configuration to run something else at "startx". Once you're in X, you can open up a terminal (Xterm, Konsole, Eterm, etc.) and then type in "kppp" at the command prompt. Your Kppp will launch and you can dial from there. Hope this helps out.