Minor update -
I created a new Harv's Knoppix CD (2.6.11 kernel) and it exhibited the
same problem. I then remembered that the AFU version of Knoppix would
load 2.6 (2.6.9) as well as the default 2.4 kernel. Once again, same
problem exhibited with the AFU version and the 2.6 kernel.

Next, I tried the same thing on a Desktop PC. First AFU Knoppix with
2.4 kernel, the baycom worked perfectly. Then both AFU and Harv's with
2.6 kernel, same Tx problem with each one.

I may try upgrading the Notebook PC to 2.6.14 as soon as time permits.
Hopefully that will make a difference.

Also, when I posted the message here originally, I had not been
thinking in terms of a kernel problem, I was thinking that I was
mis-configuring something. I have since done some Usenet searching
specific to Baycom serial / 2.6 kernel and it appears that others are
having the same problems.

Dean KD4TWJ