This afternoon during the checkout, the secondary once again complained 
about the E axis not stopping on a full step.  Unlike the last two nights, 
I was able to change the focus, tracking the same position the telescope was 
last slewed to.  Only when the altitude axis position was changed did the
error crop up, and it happened immediately upon moving.  Like previous nights,
homing the E axis restored proper operation.  The position error was 49 
counts from the homing status info.