D-550 solo mode doesn't work correctly

[cromdubh]

Whatever buffer that is used to remember held notes during solo playing doesn't appear to be working, it seems to "forget" those notes once a new note is pressed. For instance, it's a pretty common technique with lead playing to hold one note and then hammer on and release other notes while still holding that first note. Like hold C, then hit/release D a couple times for a trill. The sounding notes will appear C D C D C because the held C retriggers after D is released each time. Well mine will just play C D (gap) D (gap)... In none of the solo modes do those held notes retrigger. It makes it semi-useless as a lead synth currently, and I wouldn't even know how to go about diagnosing this problem.

The version it's running on is 1.01. Does anyone think that it would be worth upgrading to 1.02 and if that might actually have an effect on this or if that's a waste of time? Any other ideas? It's an oddly specific problem that seems like it would have to be at the chip level somewhere. I doubt simply a bad tracer or joint would explain such a problem since the unit works perfectly in all of the polyphonic modes.