Aaaaah, oh well. LOL I didn't see this edit function. I was looking at the right hand side all the time.
Thanks, now I know.
Yeah, tab slows everything down but the lag I am talking about happens only in two of four rooms (rooms are identical, same entities, segments...). And I have looooads of rooms on my map. Therefore, it isn't a problem with FPSC version or my computer. Everything runs fine. The problem must be the layer below. Two of the four identical rooms have corridors below and LAG. The other room don't. Hm.
EDIT I created a door and jumped out of my house.
1...the room with lag.
2...the corridor below.
3...other room, same as 1 but without lag.
4...things under 3. No lag.
What's the problem? Should I create ANYTHING - without using it in game - under 1, only that there is something?
[under construction]