Rigid bodies passing through [Blender 2.73a]
I have a scene, where a helmet is falling on a surface.



It is quite complex: high-poly helmet, every link in chainmail is a separate element and all this stuff are rigid bodies. I want them to act physically correct, that is why so. All modifiers and transformations are applied: objects are clean meshes. I've already done simulation tests with this model earlier (https://www.youtube.com/watch?v=gszj0GUkigI), now I've updated the model and try to make a new simulation, but it fails:



Surface (was a passive body plane first, now an active non-dynamic cube — doesn't matter) first collides, but then chains and helmet pass through it.
I've tried everything — no idea how to fix this.

Here are screenshots of settings:

Helmet:



Chainmail:



Surface:



Scene:



(all objects are real-size, high values of steps and iterations always well helped increase accuracy)

Any ideas, why is this?

UPD

Subdivided surface, increased steps to 1600 and solver iterations to 120. No luck
Well, with some tries I've come to understanding, that problem is not in the surface, but in chains. In Blender's physics engine mass is corresponding to durability (sic!). So, realsize chains with a calculated mass near 1g each is too weak and they "break" during collisions. The only working workaround was to scale everything up several times and increase the mass of everything...