When I enter the fighting chance, the swords (at least some of them) fall from their racks. Same happens in a few other loctions, items just tumble around, even though I am no where near them.

Does not happen everywhere or everytime. Usually I have OOO and MMM in my load order and no mods that affect anything to do with physics.

Known quirk of Oblivion or do I have a problem?

That's havok for you. It just happens, along with some other strange oddities.

If the original placement of an object is unstable, it will fall over when the cell resets, which is actually deferred until the player enters it. So the same stuff will do that every time you back if it's at least the three days later. It frequently happens with mod-added items, because the mod authors forgot to run the Havok sim in the CS to let the item settle before saving the esp (and I've done that myself a few times).

Using the enhanced grabbing mod gives you an opportunity to gain disposition points with everyone that sees you pick up the item and put it back.

Like helping old ladies across the street?

Thanks for the tip ITPaladinn, I will give that a go. And thanks for everyone who responded. Glad to know I don't live in an earthquake zone!

mostly its placement and running the havok sim.

it also has to do with the actual havok settings. Solver Deactivation to medium will make piles of non statics, like clutter, rest more stability.

also inserting a bhkConvexTransformShape above the shape will sort out some of the bounding issues people commonly have on havok items. Like when people complain that books react to other books when they aren't actually touching, like if you take one and all the other books in the shelf go bonkers. if the transformshape is present, the collision shape won't react until it actually collides, if you see what i mean. usually what happens is that there is some amount of space outside the collision object that is react-able. Dunno may not work with Ob. just random stuff that's come up in F3 modding. I guess its backward compatible.

I have an issue with a pair of shoes falling through the floor into the main entrance in one of the guild halls. Sometimes if you time it right it hits somebody in the head.