USB seiral at 50-Baud problem

[Forrest Myers]

I'm writing an RTTY program thathas to work through a USB to serial 
converter. It works if I set the baud rate to 150 Hz but fails at all 
speeds below that. At 150 Baud and above, the sending is normal. Below 
that, the thing just puts out a blip every once in a while. Since ham 
RTTY runs at 45.45 baud 5-bits this will not work.

Any ideas on how to get a USB to serial converter to run at 50 Baud?

I'm running Ubuntu 8.04 with all the updates.

73,
Forrest
AG4ND