Not seen this myself, although I know the occlusion is still in need of work. Occlusion is nothing like as effective as it should be in my opinion, but I have said this several times in the past.
It needs some TLC to be honest, I can't see how it can ever work effectively with one slider to control it. We need a minimum and maximum distance for it to work reasonably from my experience in coding over the years. Using one slider to control it seems optimistic and unrealistic at best. I'm only going by my own experience with DB, which was limited to hiding specific objects rather than parts of the object, which is beyond me.
As far as I can see, the occlusion only works on a per entity basis, rather than per polygon. In which case I believe a minimum and maximum distance is required for it to be effective. You only have to witness the pop up issues apparent at the moment to see that. Working with object size and distance alone will never work 100%. Turning occlusion off should fix it, but in that case it's pretty useless. I have not found a real world level to work well with occlusion to date. I've sent levels which got fixed in the past, but always default media, which is pretty useless to anyone wanting to make an original game.
I could be wrong, it could just be a matter of tweaking the system used, but really for overall use to make an original game, I think we need more control of the culling system. I have sent various examples to TGC of the popup and general issues of occlusion, but all need to be default media, which in all honesty doesn't really help. I still have issues with custom levels, which I can never get fixed because I am always asked for a default media example. I do my best to recreate the issue, but it never fixes my custom level.
For now, just disable occlusion. Perhaps it will work effectively in the future, at the moment it just doesn't seem to work properly.
SPECS: Q6600 CPU. Nvidia 660GTX. 8 Gig Memory. Win 7.