Right....

So very weird this - after my render had finished I started a blank scene and then checked the open gl software option and also unchecked the anti aliasings.

On re open - vue crashed.  3 times.  Then finally it said it'd detected conflicts and did I want to reset factory defaults.  I replied yes.

Now I can load 2 terrains and they both show as meshes BUT when I add a 3rd, the 2nd goes to the flat grey box.  Resources are at 75%

I'll raise a ticket tomorrow

Gill