flexfax: Comm failure during phase B/C

[evan@telly.org (Evan Leibovitch)]

This is my second request; please help. I have spent even more time
going through the HylaFAX documentation and can't get to the bottom
of this problem.

The system is a Linux (2.0.29, Caldera distribution) in which
receiving faxes work perfectly. Sending always results in the same
error: "Communications failure during Phase B/C".

If I try to send to another system with (a well-working) HylaFAX,
it (the receiver) sends a "facsimile not received" notice that

"An attempt to receive facsimile on ttyXX failed because: COMREC received DCN"

Session logs are available; I didn't want to clog up the mail list with
them. The troubleshooting parts of the docs don't seem to provide any
clues. And I've tried changing from hardware to software flow control
with no chance in result. Any suggestions?

Can someone even suggest pointers where to look? Specifically, can
someone tell me if any TTY parameters or ioctls are changed at the
point where this error occurs?

Thanks.
- Evan