oh wow, its right there... its weird how the maya interface just disappears without you doing anything to make it go away... like when the view cube just vanished... its not like i had played with that in the settings but there it was unticked... and my mental ray vanished as well... i'd bring it back by loading an old .mb file that had previously been used with mental ray and that worked, but this plug in manager is better... wonder why things just go unticking itself... Had those 2 problems myself, and then I found the cube in the HUD, although I just find it a gimmick, I navigate by the mouse. My MR usually disappears after an action has crashed Maya (for example if I exaggerate with mesh smoothing and then everything crashes due to too many polys).