ok i've changed my plugin, so it excludes everything else and i can post the exact code. As you will appreciate its the same, but i realize its easier to help if you see the full code. It hooks at global_start and just contains:
So i get only "Test Output =" as an output. The $vbphrase[unread_x_nav_compiled] is not displaying because i presume its populated later on than global_start? either that or i'm just being a complete idiot (which wouldn't be the first or last time )
If anyone can help, it would be greatly appreciated. J.