Thank you, lagagnon, for the info.
Yes, the modem is detected and yes, I can connect to the Internet!
What did I have to do?
1) Change the hardware jumper on the modem to option: PNP and IRQ3
2) Using 'Chestnut Dialer' to configure the modem...
Enter for Device: /dev/ttyS2
That's it... Problem solved...Case closed!