Symptom
When attempting a PPP connection, an alert box with this message appears:
"PPP Connect Error. No dial tone detected. Check phone line connection and try again."
Solution
This occurs when a modem in the nation of Italy encounters a nonstandard dial tone or line signal.
Note: Updating to Mac OS X 10.1 resolves this issue. 
Users of Mac OS X versions 10.0 to 10.0.4 may follow these steps to ignore the dial tone:
1. Choose System Preferences from the Apple menu. 
2. Click Network. 
3. Set the Configure pop-up menu to Internal Modem. 
4. Click the Modem tab. 
5. Be sure that the option for "Wait for dial tone before dialing" is not selected.