You may need to enter in your modem initialization strings codes, ATDT etc:
| The precise behavior of your modem can be modified by using a specific
„ modem initialization string, to adjust the settings of your modem, or
„ to modify its default behavior. You may enter a modem initialization
„ string here.
„
„ Many modems will work correctly without any special settings. If you
„ leave this field blank, the default string of "L0M0" will be used. This
„ turns the modem speaker off, so that you will not be bothered by the
„ noises that a modem makes when it starts a connection.
Maybe your modem(s) need to be told to wait for a dial tone before dialing?
For your modems to start handshaking before dialing is very, very odd.
Hope that helps

Cyrus Bharda