TAPI, TAPI, TAPI...

I am writing an application that uses TAPI and I am having trouble recieving certain messages in my lineCallbackFunc() function. I am using the class CTapiLine, provided on this site, and my code is as follows:

void CTapiLine::TapiCallBack()
{
switch (m_dwMessage)
{
case LINE_LINEDEVSTATE:
{
switch (m_dwParam1)
{
case LINEDEVSTATE_REINIT:
{
m_Status->AppendString("LINEDEVSTATE_REINIT...");
break;
}
case LINEDEVSTATE_RINGING:
{
m_Status->AppendString("LINEDEVSTATE_RINGING...");
break;
}
break; // LINE_LINEDEVSTATE:
}
}

...




The message that I cannot recieve is the LINE_LINEDEVSTATE message. Because of this problem, I do not know when the line is ringing so that I can tell the user to pick up the phone. I can't understand what is wrong because I am having no trouble recieving any other messages with my callback funciton. Please help with any suggestions.

Mike Dorsey