BSP vanishing problem.

[Zurginator]

Ok, so I started messing around with the editor today and I've run into an issue with the BSPs I've been using to rough out my rooms.

I've roughed out 1 room, it has a floor/celling/4 wall BSPs. If I go and create the floor BSP of the 2nd room, the floor and left wall BSPs of room 1 disappear. They still exist according to the editor, I can select them, etc, but they will not render. I've tried rebuilding everything, and even loading the map up in the client, but they just will not appear.

Anyone got any suggestions? Thanks.

Edit: Update:
If I delete the floor, the invisible objects come back lacking their textures.

[ilguano]

Could you post a screenshot? Also could you post your system specs? What graphic card are you using, etc. Any other related info might help (UDK build you're using, etc).