I've had some serious tuning problems recently. The two oscillators have been slowly drifting out of tune. Especially OSC 2. Any of the presets that use both oscillators have been sounding pathetic.
Fortunately, Moog has a firmware update available. The new O/S has several calibration tools for tuning. They take about three hours to run, but they work. The new O/S also has an auto-tuning feature.
Not sure why my OSC's needed calibration so soon. (18 months?)
How did Bob Moog manage without firmware updates via midi ?
http://www.moogmusic.com/manuals/TE%20Update%20Manual%20Rev1.pdfClay