Web Player prefab issues

Unity web player doesn’t seem to instantiate prefabs that are attached to scripts.

Do they have to be located in a specific folder? Or maybe referenced differently?
(currently in the scripts they are defined as: var prefabName : Transform)

Everything works fine in Standalone version.
Other parts of the game (textures,scripts) work perfectly fine in the web player.

Just for further reference, it worked by re-building the project - something probably crashed the first few times, try and not have many other applications open during the build process.