It's really hard to explain what exactly is happening in this cell - it looks like there's no collision on the floor or something...
The same problem is with walls - I can go through them like a ghost.
Other cells does not have such problems.

Alright, here's the video:

http://www.youtube.com/watch?v=VuTLfgbaxNk&feature=channel&list=UL

Please help somebody.

I've seen this before, don't know why it happens but, the only way I've found to fix it is delete the tiles that seem to have no collisions, save and, quit the GECK. Restart and, replace the deleted tiles with the same tile you deleted. save and, test.

If that doesn't work then add collision plains to cover the suspect tiles.

hope that helps,

cev

Thanks but it doesn't work.
Another suspicious aspect is this:
When I place a havokable object on the ground and activate the havok button, object falls through like there's no collision on the tiles. This was happening from very beginning - the cell is a duplicate of Camp McCarran Terminal. Although, I was testing this cell some time ago and I could walk here without any problems. So the following questions are: what caused such horrible bug and who can say it will not happen with my other cells?

If you want, send me the file and, I'll take a look at it. I have had the same issue from time to time and, was able to fix it.

cev