I hope this doesn't get complicated. I've been trying to solve this
problem for a few weeks with no results.

Problem: I can't get playback of MIDI tracks in Cubase SX 2.2

Hardware Set-Up:
Windows 2K says all devices are installed and functioning brilliantly.

-'MIDI Out' of Roland JX-10 synth to 'MIDI in 2' of Edirol UM-550 '
-'MIDI Out 2' of Edirol UM-550 to 'MIDI In' of Roland JX-10 synth
-1/4" Phones/Stereo Out of Roland JX-10 synth to 1/4" Echo Mona 1 In
-RCA Echo Mona 1/2 Out to monitors

-Edirol UM-550 has Input 2 patched to Output 2
-Using menus on Roland JX-10 synth, set 'Patch Memory' to channel 3,
'Upper' to channel 1 and 'Lower' to channel 2. 'Upper Local' and 'Lower
Local' are turned off.

Software Set-Up:
In Windows 2k, I have the preferred Sound Playback set for Mona Analog
1-2 Out and preferred Sound Recording set for Mona Analong 1-2 In. The
Mona sotware mixer (version 6.08) appears to be working properly.

In Cubase SX 2.2 manual, they recommend turning on "MIDI Thru Active"
and setting the Local to Off on the synthesizer. This has been done. At this
point, everything seems to be working brilliantly (except for not figuring
out the S/PDIF thing. That's the least of my worries though). I open up
Cubase SX 2.2, I start a 16 track MIDI sequencer project. On MIDI 01
(the first available MIDI track), I choose the Edirol's MIDI port 2 for both
my input and output, I set the MIDI channel to 1 for the track. I leave the
Programs and Bank options off for that track. I click on the Monitor button.

From here, I press the keys of the JX-10 and all sorts of bars appear
active in Cubase. MIDI In and Out activity shows on the bars as well as
audio activity from Input Channel 1. I hear the synth play through the
monitors (but the bars, oddly enough, don't show activity in the Audio
Activity Output Channel 1??) . The Input and Output indicators on the
Edirol MIDI interface both blink. Excellent, right?

Ok. I hit the record in Cubase. Press keys on the JX-10. Get sound
through the monitors, MIDI in and out data is being sent. I stop recording
and my MIDI track with all the events show up. Right on. Now let's play
that MIDI track back. Crap. The only levels I'm getting are on the MIDI
Out Activity bars of Cubase. No audio playback. Hrmmm.

Experiment 2: On MIDI 02 in Cubase, set up the Out on a VST plug-in.
I press keys on the JX-10. This time, I get MIDI IN and Out activity and
actually get activity on the Audio Activity Output Channel 1 bar. I record
using the plug-in as the Out and play back. No problems at all.

I think I've covered all my bases. So why the fricken-frack can't I get
audio output from external MIDI tracks? Is MIDI Out data from Cubase
not getting back to the JX-10 to tell it to create the audio? If so, why?
If not, any other thoughts on why I'm not getting play back?

I wasn't sure where to post this since it could be either a wiring, synth,
or sequencer issue. I'm really trying hard to
figure this out on my own but it's been a challenge.