waveInAddBuffer() doesnt fill my wavehdr

I have some difficulty of recording sound from modem. After I send a wavehdr to modem to be recorded, the modem doesnt seems to fill the buffer if i keep silence, eg:

05-11-2002 23:03:45.83 - Received DLE Raw=115, Translated=41.

i want to record the sound from modem regardless the silence/non-silence state of the line, any idea, please.

thank you for reading my post.

Tze Yuang
[415 byte] By [ctyuang] at [2007-11-17 11:49:53]