I'm finding some of my old keyboards, modules and control surfaces are occasionally sending out intermittent MIDI messages to Midi Translator. Can't blame MT for responding to this gibberish in unexpected ways!!
All I can say is really exercise all the buttons, sliders, knobs, etc. on your product and hopefully that will clear up most of the problem.
In my case, a momentary button on a module was occasionally sending out a message to a slider instead. It wasn't the button's fault as I can tell. Seems that the slider on the module was dirty and the action of pushing on the button mechanically activated the slider and it decided to send out it's message. Roland scans their control surfaces and the first one that speaks up gets to rule the roost. (does that make any sense?)