I had posted this problem (slightly different angle as I believed I was having a hardware issue) under hardware but the reply I got led me to discover that the problem I thought I had didn't exist and that I have a software problem.
I have a dual boot PC running SuSE 8.0 pro (kernel 2.4) and Windows XP. The modem I have is the Intel 536ep v.92 controlerless modem. Windows installed the modem and it runs prefectly whereas linux is unable to see the modem. I've downloaded the relevent drivers form intel. I've made and installed them (make install etc...) but to no avail. Is there anything else I need to do?