I'm running into this issue frequently when using TP.....pretty sure it's just human error (me being the human).
I use an emitter to shoot (Group A) particles that hit a deflector (set to event only), which change them to (Group B). Group B hits another deflector, and that changes them to group C...and so on.
My problem is at the frames where particles switch groups.....theres is always a static frame of a single particle...or a group of particles. I've attached 2 movie examples of what I'm talking about. Both are using mograph cache tags...but I encounter the same issue frequently without cache tags.
The second movie (not the cross-section with the pink spheres) is set up with emitters shooting particles towards geometry using the PPosition Follow & PVolumePosition nodes......Same thing happens with static single spheres revealing at the frames in which the change in groups occurs.