Particles suddenly starts bouncing!

I’m facing a weird problem in blender 2.60, when working with particles bouncing on a collision object. The particles should damp after two bounces on the collision object. When i playback the particles behave perfect the first preview, but when I playback a second time they suddenly keep bouncing on the collision object. When i move a random slider on the collision settings, same story. 1st time everything is fine, 2nd time particles keep bouncing. Anyone familiar with this?

Allright, I trashed all the emitters and collision objects and rebuild it. Now they are acting fine, so problem solved :confused: