S1000+ Oscillates when yawing.  Any ideas?

It's hard to imagine what's the oscillation looks like from your description, you'd better post a video of that.
You use an A2 Flight Controller? Check your center of gravity. I think we need the data to evaluate.

I had my new S1000+ A2 hover about one meter above ground.
The S1000 + is hovered for a few minutes stabiel. No one touch the remote. I made some tests. Then the copter has been rocking and routes tilts sideways.
And crash on the ground.
Then the splinters of the propeller are flying me around the ears.
In addition to the propellers nothing is apparently broke. But I do not trust it, because I did not find out what happened.
If last it happened at a higher altitude, would have the S1000 + a total loss.
This is a picture of my jacket I, when it was hit by the Propellers.

knarfboy Posted at 2015-3-17 05:50
I had my new S1000+ A2 hover about one meter above ground.
The S1000 + is hovered for a few minutes  ...

My friend, could you pls send your flight log to me? autumn.a@dji.com

I have no flight log. But now i have installed an iOSD Mark II. Next time i have a flight log.

The S1000+ was hover, I've heard that has changed the sound of the engines / propellers.
The Koper has then been unsteady. The flight then became restless, and is tilted away to the side.
This has gone very quickly.
I have replaced a motor mount too, this has come loose.

that you changed the Props?
If your Motor mount was loose (The bolt in the rubber) explans the oscillations, check all and also the quality of the rubber or some damage

Before the Crash the Motor Mount was ok, the S1000+ was new.
When I replaced the broken propeller, I have regularly checked the engines. And I've found that this engine mount was also defective.

Thanks for the relies.  I solved the problem.  An unleveled IMU was the problem, solved by carefully leveling the IMU with a precision level.