I would certainly check that the store/non store switch is actually latching and unlatching properly. This may seem obvious, however, I have seen many of these type of switches that were gummed up or victims of corrosion therefore, not latching or making proper contact. Also perform the storage calibration checks and procedures outlined in the manual, Sec. 8 Adjustments Section. Also check Q1396, VR1396 and their related components for proper voltages and failures. I have a 577D2 that has been converted to a D1, I am following your posts regarding your troubles.