1.Check to see what phone number they are dialing in DUN settings in "My Computer".
2. See if the "1" or area code needs to be dialed for long distance.
3. Dial the number from here and see if you can connect (if not it is not the member's computer).
4. Have the member dial another access number in a nearby area to see if that will work. May be number.on their handset.
5. Have the member dial the number on their handset.
6. If none of the above works, then start looking at their password, network and modem properties.