When the Fix Lag =1 is when you have jerks, right?
Yes that's right.
When A is pressed (LagFix=0) do you still get the odd little skips though? or is it rock solid?
I can see very minute skips now and then. Compare this to Torque2D, now on my PC that is rock solid as far as scrolling the screen is concerned I've never seen it skip at all.