hi there what sort of modem do you have,
external usb modem or external serial modem
I realy need to know this because linux only supports serial modems.
it's because they are all hardware modems, USB PCI AMR are mostly software
modems. this means that they are cheap but use software and these require
big drivers. since no manufacture wrights drivers for linux, USB PCI AMR dont work in Linux.
I would just buy an serial modem, like many others, I am using one now, have a look around
this site you will soon find out
I think you are getting this problem because your modem is not supported by linux
but am not totally sourer, yet