I have the same problem, I have configured IVM for 8 rings before answer, still callerID is unknown. Before installing this software, I used a caller display answer machine which works fine.
I have an Intel 536EP PCI Modem, acording to Intels website, it does support Caller ID.
When I run Query, one section which is bugging me, is AT#CLS=? , Response is COMMAND NOT SUPPORTED.
Is AT#CLS the Caller ID ?
suggestions please?