Hi,
I'm sorry but I'm not aware of issues with this specific type of modem.
From your description, it would appear that the modem doesn't receive data.
Did you verify you use a proper 5wire cable between PC & modem?
The modem was replaced with a modern USB attached USR Modem. Now everything is working fine except for an intermittent problem with sending files. Occassionally the VAZModemTransferEnd(Sender: TObject; ExitCode: Integer); event fires with exitcode = 0 even though the last bytecount from VaZModemFileProgress(Sender: TObject; ByteCount: Integer); is only about 60ish% of the entire file. We can see the progress from procedure VaZModemFileProgress go up as I compute the percentage inside the event. It shows 5%, 10%, 15%... 60% and then suddenly the TransferEnd prematurely fires. The BBS on the receiving side is still in file transfer mode and is expecting more zmodem packets.
It looks like I'm using v2.01 of the Async32 package. is there anything newer?It's unclear what version you use. The latest version is v1.4.5.0. See: http://www.tmssoftware.com/site/async32.asp
With this test you could exclude it is caused by noise on the line.