Item-Glitches in 1.4.2 ?!

I kinda like the new update. But now I have a big problem updating, because player would just abuse bugs because of my freebuild world. It's a creative world. I'm pretty sure they would just start making nether portals and throw items in there. The point is: how do we prevent it? There are no plugins to disable that for now. I'm using CreativeControl to prevent people from using XP-Bottles and glitch XP. But if I prevent them from using obsidian or flint and steel, it kinda sucks. Is there a way to prevent nether portal creation in a specified world?

Edit: Or even better: is there already a plugin to prevent that?

 

Why would it matter if it is a freebuild server? If you don't wan't people sending items to survival's nether, use Multiverse-Netherportals so that the world has it's own nether.

 

It's not completely a creative server. Mostly survival, but there is a freebuild world, you can instantly switch to by command (MultiWorld). That's why I don't want people to just throw the items in the nether, go to survival, get back in the nether and get the items they want.