version v119 and the latest beta had some collision-problems that may came from a coordinate-change that scene commander did in v119.
nonstatic entities/characters seemed to level up or down around "10cm" to avoid framedrops through collision-probs, was my guess. scene commander is aware of this and it should be corrected with the next beta/finalv120. you can avoid this problem in setting the item to immobile and "enter-placing" everything, wich works fine for me to avoid this kind of "safety distance".
@thraxas:
Quote: "Also as I had downgraded on purpose I hadn't realised how the new culling system makes object disappear when you're only 3 steps away."
had the same issues when updated to v119, deleted temp-folder and clean fpsc, experimenting cullmode=1,cullrange=700+ OR cullmode=0 in setuplevel.fpi or in appear-scripts used. after replacing the item and maybe set object to always-active worked for me somehow, but i cant say what exactly was, but now it works besides the collision-problems, no issues with new-placed objects since v119.
edit: too late, commander has spoken.^^