I have upgraded to Acelleration and the A/P works now both for elevator increase and decrease but one problem remains.  The aircraft is porposing (rocking up and down) as it tries to maintain pitch.  Is anyone else experiencing this issue and how should I try to fix it.

Note that I have added most of the mods and I am on latest version 2.4 (or at least I should be as I purchased in the last 2 years).