Can't destroy objects (even on loading a new scene) and get strange silhouttes remaining

I'm having problems with phantom objects remaining after kloading a new scene.
I started out just loading a new scene and expected the objects to vanish - but they didn't leaving their silhouettes on screen.

So I tried destroying them first (I'm destroying the objects in a Playmaker FSM - then using the next state to load a different screen).
But I still get the same result.

It seems to be a rendering thing - as changing from the game window to the editor and back seems to wipe it. - But it also shows up on a build.
I'm using deferred rendering. The material is a simple diffuse.
I do have one gameobject that is set to be not destroyed on load which I use for global values - but its not in any hierarchy or parent to these meshes.

I've attached an image showing this.
The top image is the mesh models on one screen before destroying them.
The second image shows what they look like after being destroyed - even after loading a different scene.

Help!

 

The objects don't seem to be retained - if I resize the game window they disappear - its probably a rendering issue - but its the same on every machine I've tried it on. I get the same result either in the game window or in a build.

I'm going mad trying to figure this out and haven't seen any online clues.

 

Try disabling any plugins or scripts that may do any kind of camera effects.

 

Thanks - but there aren't any.

I'm even using the standard materials - but I am using NGUI and Playmaker. UI elements are fine - its just meshes that mess up.

As soon as the window is resized the effect vanishes. So its not the object remaining in memory as I first thought.

 

Have you tried removing the UI background from behind the mesh and see what happens? It looks like it's not re-rendering what's behind the meshes when they're destroyed. Is that UI back there made with nGUI?