Synway and NCH have been working together to try to develop better drivers for the US. Synway is currently working on a driver that should have no problems here in the United States. Until then, please make sure that your config file is set up with the following information.
United States of America
Busy tone - 600x120//600x133//600
x140//600x160//480+62
0.5 on 0.5 off
Confirmation tone - 350+440 3x(0.1 on 0.1 off)
Dial tone - 600x120//600x133//600
x140//600x160//350+44
continuous
Annex to ITU OB 781-E 27
COUNTRY/TONE FREQUENCY in Hz CADENCE in seconds
Recall dial tone - 350+440 3x(0.1 on 0.1 off) + continuous
Intrusion tone - 600x120//600x133//600
x140//600x160//480+62
0.5 on 0.5 off
Number unobtainable tone - 200//400 0.5 on 6.0 off
Permanent signal tone - 480//400//500 continuous
Record tone - 440 0.5 on 5.0 off
Ringing tone - 420x40//500x40//440+480 2.0 on 4.0 off
Re-order tone - 600x120//600x133//600
x140//600x160//480+62
0.3 on 0.2 off
Warning tone - message (4) 1400 0.5 on
Call waiting tone - 440 2x(0.3 on 10.0 off)