I've had surprisingly good luck with the HiRo USB modem (Agere/LSI Soft Modem) on my PSTN analog line connected to a Panasonic PBX. IVM 5.11 works fine with everything I've tried (running Windows 7 with that most recent version of the modem s/w, ver 2.2.98.0), EXCEPT for one critical failure.
When the caller presses a key (say, '2'), IVM is supposed to flash, dial ext. 215, wait for an answer, and then hang up on answer or fail back to the call tree if no answer. I monitor the progress of an incoming call. The modem recognizes the incoming DTMF tones without fail. It correctly applies