This is a bug I noticed before the patch, and I see that it's still in the game.
Sometimes when unloading weapons, the ammo you gain appears in your inventory, but a second later it disappears completely. I don't know what affects it, but it happens quite a lot.
EDIT:
New bug. It seems whenever I get close to the rookie village (with sids bunker), the opening dialog Sid uses always starts. When I get to the bunker itself, it seems that Sid was doing the scene from the start of the game. And this happens every time I walk away from the village and then come back to it.
It might have something to do with the fact I quick saved in the middle of his opening speech, restarted the game, and loaded that save. I'm not sure though.