RAS or hardware problem

I had to install a 25-pin serial port on a new server. This was to connect to a IBM modem. The computer sees the modem and will answer calls. The problem is it stalls out during the user ID password verification. RAS is setup identical to the other RAS/modem combinatio that is working. RAS has been reinstalled serveral times, with and without the service pack. There are no errors in the EVENT log. The event log doesn’t even show the attempted log on.