I already have checked my interpolation as being linear.
What i did find, is if i added a single keyframe anywhere within my two null movement keyframe sets, then dragged the extra keyframe over my first null keyframe movement, then for some reason it cancelled out any unwanted movement i had been experiencing.
I still dunno why i had that movement to begin with, what its called, and now i dunno why adding the extra keyframe made it better.
But thanks for your effort to assist me.
Learn the Curve… Ride the wind!