Genete wrote:I have no idea why at frame 31 in my case the layer doesn't follow the path (almost the last path!)
Genete, I have a feeling that it is because your "particle lifetime" is set to 30 frames...
It is not related to particles. Create a layer, move it during some keyframes, set the "Rotate to follow path" option. Then you'll see that at the last layer displacement keyframe, the rotate to follow path loose its effect. I think that AS needs almost two keyframes to calculate the "path".
-G