When I was working at HN systems it was good with little levels, where not much pawns and other dynamic things. There are few reasons based on an original code of AI and glitch Karma (Math) physics engine.
As well I found problem with pickups travel buffer, more than ~200 pickups on level will crash original P2 (after few levels), but lately I fixed it in HN.
You can remember the problem with Forest, which was caused by some pawns, which was recursed somewhere.
All crashes causes by one time iterations, and Karma errors.
For example, 250 calls is a function recursion, and 100000 iterations is a cycle recursion, which are classis problems of P2, it can crash game with a lot of weapons or pawns.
As I wrote, Pawns and Karma are potentional crash-causers.
But not all so bad, we can do something.
![Obrazek](https://cs623128.vk.me/v623128011/298d8/92e2jk-wWTM.jpg)
My suggestion of geting better stability is to change 3 options (Bystander population, Corpse population and Ragdolls)
BTW: limbs (hands and legs) are karma too, it uses same limiter as body ragdolls.