Your problem lies with the modem, Time install Infonexus units, and the drivers will only allow you to connect to Supanet, go to www.conexant.com and download the HSF driver, If you are in any doubt you can also download Conexant's 'listmodem' tool which will confirm (or not) if you can use the generic driver.
Your problem will then dissapear. By the way, Supanet is one of the better dial-ups around, I have used it as a back-up to my NTLworld dial-up prior to having broadband, and found it quite good.