HI,
This unknown extension that keeps pooping out, is it under the modem section? is it appended to your modem? is your modem showing? Have you tried to go through the install procedure from that position ie. click on the tab and update the driver using the 33.6kbps driver as mentioned above?
Also, is the modem configured correctly - have you got it set to pulse Rather than for Tone?
What settings are enabled on your modem settings etc.
I am presuming from what you are saying that the modem is hearing the tone on the phone line and is attempting to dial out - please confirm this by checking that the modem is set to wait for the dial tone before dialing.
hopefully (he said crossing his fingers) you just need to change the modem signal to tone rather than pulse.
Please post back - I am not very far away for the next 90mins - things are steady at work, then off to the pub ;-)
Regards. It not what you say but how you say it that counts...apparently.