X2P MIDI, Note Off, versus Note On, Velocity Zero

Driving a second Obey 70 light controller, via a USB Midi controller, piped thru Sonar, and out a DIN port.
 
The first rig, a live DJ, PA and light show rig, works perfectly, but is a pain to set up and tear down, making programming impossible.
 
The second rig, a close approximation of the first, permanently set up in the studio, allows perfect control of the lights by the MIDI controller, Live, but, fails when playing back recorded MIDI.
 
Monitoring the output I see the expected Note On and Note Off messages from the "thru" datastream. The playback datastream, however, substitutes Note On, Velocity Zero messages, for the live stream's Note Off messages.
 
This definitely confuses the Obey 70.
 
My theory is that the Obey 70 is trained to both expect, and ignore, a Note Off message, for every Note On message it receives. Since it never gets any Note Off messages while playing back MIDI files,  it seems to ignore the next Note On message instead.
 
Since the Live Rig doesn't have this problem, I assume whatever difference there is in play, is more likely to involve a Sonar setting, than a difference in the Obey 70 firmware.
 
How do I get Sonar to record, and playback, exactly what Sonar is passing thru my system, while I'm recording?

Turns out the problem is a combination....Sonar playback, MidiSport 4x4, Obey-70. The problem follows this combination from computer to computer, from Vista to Windows 10.
 
Sonar thru-put while recording works perfectly, but playback, thru the MidiSport into the Obey-70, does not. Thru a different interface, it works. Thru the MidiSport, Sonar playback drives a DX-7, and two Midi monitor programs, fine.
 
Ableton playback, thru the MidiSport, drives the Obey-70 fine.
 
I can only guess there is some slight difference in the datastream waveforms, either timing or shape of the square wave bits, that Sonar does differently on playback, that the MidiSport enhances, and that the Obey-70 is sensitive to.
 
I'd really like to know why this happens, it seems important to be aware of potential problems that Midi monitors cannot detect, but I have a Roland USB/Midi cable on the way, and fingers crossed that I can get back to programming lights.