Problems setting up Midish to work with my Midi interface, keyboard and sound module

Hi everyone.  I have just started using Midish under Ubuntu version 11
and am attempting to set it up to work with my keyboard and sound
module.  I have an M-audio Midisport and have my sound module
connected to its first output port.  My keyboard is connected to its
first input port.  According to Aconnect, the first port of my
Midisport is called "20:0".  When I send Midi files to 20:0 using
Aplaymidi, they play successfully on my sound module.  When I launch
Midish, however, they do not play at all.  The command I am using to
connect my sound module to Midish is:

dnew 0 "20:0" wo

The command I am using to connect my keyboard to Midish is:

dnew 1 "20:0" ro

Could anyone please advise me where I'm going wrong?  Midish is not
producing any errors as far as I can tell, but Midi files I have
imported into it definitely do not play.  Nor does the Midish demo
song!

Many thanks,
John