Reproduction steps:
1) Download users project, enter test scene.
2) In hierarchy select ParticleSystem.
3) Notice object has collision enabled under Particle System component.
4) In the Scene/Game view notice particles jitter when resting on the surface.(both in editor and in play mode - see the gif below)

Reproduced with: 5.3.0f4, 5.3.0f1, 5.3.0b1, 5.4,0a6
No regression since there is no 2D Collision mode under Particle System collision tab in Unity below version 5.3.