Level Editor Problem

[Reeda]

Hey guys.
Recently I've come across a problem in my level editor that stops me from being able to add decals, static objects and planes to my maps. My maps are small compared to most and don't contain many objects. It is worth noting that this problem does not occur right away but when I go back to do some editing to my maps. In the actual level editor there are no problems and I can see everything I've placed, but when I enter the game to test the level everything that I placed since the last save seems to be missing.

I'd appreciate any responses on how I should go about solving the problem.

Cheers.