Bumps during cruise

[hefy_jefy]

I have been flying other planes and just came back the Comanche, I love this plane. I got the update to 1.6.
I am not sure if this happened as an effect of the update but I notice that in the cruise (8,000ft 170 KTS) there is a regular "bump" that occures almost exactly 5 secs interval, it seems like bumpy air but I am on a longish flight now and its been happening consistently.
Also if I hit active pause it overstresses the airplane.
I dont recall either of these problems previously?
Geoff