I was going to say that I hadn't seen this on my system, but I now recall there were a few instances where the pitch control on the autopilot stopped working. Usually it happened if I put on the speedbrake with the autopilot engaged. I think once the trim stopped working as well, but started again after I left the game paused for a while. I don't know what the cause is, but my mod doesn't touch the autopilot or trim.  I haven't hadn't had it happen for a while. And I have never seen uncontrollable climbs or dives.