This could be a parity problem. I remember a long time ago having a problem
like this, and it was caused by one end putting/expecting parity on the
characters (including CR) and the other end not putting/interpreting it
correctly.

At 09:43 PM 2/27/00 +0100, Olaf Seibert wrote:
>I wanted automatic speed selection on my serial line (NetBSD/alpha) and
>set up a few entries in /etc/gettytab:
>
>D9600|d9600|Fast-Dial-9600:\
>        :nx=D19200:tc=9600-baud:
>D19200|d19200|Fast-Dial-19200:\
>        :nx=D38400:tc=19200-baud:
>D38400|d38400|Fast-Dial-38400:\
>        :nx=D9600:tc=38400-baud:
>
>and in /etc/ttys I changed std.9600 into D9600. This seems to work
>partially: every 3 breaks I get a readable login banner + prompt. Input
>that I type is also echoed. However, it seems that it is not
>accepted by getty, nor being "cooked" (return is not echoed as CRLF,
>just as CR). I never get a password: prompt.
>
>Is anybody else using this, or has it bitrotted?
>
>-Olaf.
>--
>___ Olaf 'Rhialto' Seibert - rhialto@polder.ubc.     -- If one tells the
truth,
>\X/ .kun.nl     -- one is sure, sooner or later, to be found out. (Oscar
Wilde) 
>