Suse 7.3 on ibook USB modem won't dial out

Hello Have installed suse 7.3 on an apple ibook which has an internal usb modem on port usb1, I have tried setting it up with yast and yast 2 but to no avail. when I run wvdial it keeps coming back with "invalid argument" The kernel I am running is 2.4.1.2 If anyone can assist I'd be most grateful. Thanks Andy Educational Service for the Visually Impaired (Hull)