Hello, I am trying render a particle system where the particles are textured planes, but sometimes the particles will rotate, and then randomly stop rotating. If I start the animation again, sometimes they wont rotate, and sometimes they will rotate for a different period of time. Does anyone know how to stop this? Is this a bug? Here is a video of what I’m talking about.
Particles panel --> Cache tab --> Cache Step: 1.
The default value is 10 which means than Blender stores some real values every 10 frames only and has some fun in between… errr… interpolates in between. 
The least we can say is that the interpolation isn’t very good in every situation.
With a cache step of 1, it consumes more memory but you avoid any interpolation.
Thank you, that fixed it! It’s always the little things…