I've read through the replies here and I've looked at my system. So...
1) I will increase my backlash compensation steps. However I cannot do 1/2 turn of the knob. My entire focus run from one extreme to the other in SGP only moves about 1/8 to 1/4 of a turn. I have the gear mesh as good as I can get it.
2) My focus knob rotates CW when SGP is moving "IN", (decreasing step numbers). Clicking the "reverse focuser direction" in SGP doesn't do anything, it still moves the same way. If I reverse direction in the driver then SGP gets confused because the numbers start going up, instead of down, when focusing IN and the focuser never stops. I think that due to the mechanics of my system I will not be able to get the knob going CCW for the IN direction.
The thing is, that my focusing was working well a couple of weeks ago, with good, fairly symmetric focus curves. It is only more recently that I am consistently getting the flattened right side which is why I thought there might be a change with the colder temps causing one side of the mirror to move into position more slowly.
Chris