i'm using JME + JME Physics2, and my game camera starts to tremble when a texture is loaded. It doesn't happens all the time. The program starts, and all begins to tremble, then it stops for a while and start all again.
That's a possible fix, but the actual problem lies in ChaseCamera - it cannot handle low time deltas. The current physics implementations (ODE, JOODE) operate with fixed time step size, so attaching the ChaseCamera to the physics update fixes this. The issue with high speeds you reported in that other thread, perick, is actually another one - and this needs the attaching to the physics (for high framerates, btw). Another point is that you don't need to subclass ChaseCamera or anything. Just call it's update method from the physics callback.
I know, I just did that way th fisrt time because my ChaseCamera was the default input for a DebugGameState, ans its update method was called at the State update.
Anyway, I noticed, when I ported my race game for the updated JME and Physics, that when the frame gots really slow its somehow reseting the chase camera. Don't know if something changed recenly in its implementation or it's just that when the physics update notices that more than the expected TPF has already been passed it calls the update with a different vallue. I'll check that.