No need to bother NCH staff, they aren't in the modem business and this forum produces better on this subject.
I tried the "well praised" (based on this forum) MultiModem MT5656ZDX-V. But this had trouble (more likely caused by the serial-to-usb cable).
So, after trouble shooting with MultiModem for a few weeks (free and responsive support, thank God), they pointed me to their MT5634ZBA-USB-V92 which is a voice modem incognito. MultiModem remains true to being a global manufacturer and to the success of her customer as this modem works great for the the property line example program, and you'll save $35 on an extra cable (which probably won't mesh anyway).
If you want to try this solution you'll have to get the driver through me (blumagicterritory@yahoo.com) or Matt (mabrahamsen@multitech.com), that is, until MultiModem starts delivering this driver with their product or posts it on their web page.
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