The prone deviation will affect you EVERYTIME you go prone but it also takes into account your speen and momentum
So stand still > prone = smaller deviation
Spint/Jump > prone = bigger deviation (imagine your reticule at full spread before returning to normal)
Good thing. Can't take it when some one kills me as they are diving to the ground. I've played 2142 extensivly , so I am used to it.
The funny thing is. People in 2142 still do dive to the ground like you would in BF2. Just circle on your feet, unload a clip into their butt, problem solved!