uplcom usb to serial adapter broken

[Ryan Falkenberg]

I have a PL-2303 usb to serial adapter that I am trying to make work
on my laptop that I've recently migrated to freebsd 5.3 from linux. 
After loading ucom and uplcom I can connect to and send commands to
serial devices with minicom but I cannot see the results of any
commands.  If I connect to a managed switch I can login  and type
commands but no output is ever sent back to the screen (I have
verified that commands sent from the adapter are reaching the switch).
 I have also tried connecting to a serial modem with the same results.

I have experienced the same results on my laptop and a desktop, both
are freebsd 5.3.  I can communicate properly with the serial devices
using a freebsd desktop with a standard serial port so I know the
baudrates are correct, and I can communicate with the serial devices
from my laptop using the usb adapter in windows and linux using the
uplcom drivers.  I can also use my laptop to sync with a usb
handspring visor in freebsd, so I think the usb system is working
properly.

Can anyone help me get this adapter working under freebsd?