Particles vanishing/not colliding at certain distance from camera

Hi guys my particles are vanishing when at a certain distance from the camera, only this is really close, particles stop colliding with objects and just vanish. I have tried setting fixed bounds and removing LOD and am at a loss for this behaviour.

https://drive.google.com/open?id=0B4EEPpcth1VcZkhrdmJqbWptbm8
link to project on google drive

youtube vide of the issue

hope someone can help, thanks for your time!