Wow! This is by far the best render you came up with in my opinion, and you made it in 2 mins… Ha ha funny isn’t it? Bugs can sometimes appear in maya (I’d say the user is faulty…) and if you spend more time looking for the bug, it’s better to start in a new scene. There are SO MANY parameters in mental ray that can make things go wrong, that’s why you should not play with every parameter if you don’t know what you’re doing.
GREAT! Honnestly, the gold material looks more realistic to me like this than before. The glossiness is very believable. What you’re saying, in fact, is that it has nothing to reflect! Other than the building it reflects, there’s nothing in your scene behind the camera or in the sky and that’s what we’re seeing in the reflection: nothing! For realistic reflections in scenes like this, people often use IBL. But I would stick with Sun and Sky for now.
You could add more realism to your reflections by trying this:
- add a bump map with metal rust or scratches on the gold object
- add a plane with an image or some objects (trees or background jpg) behind the camera, so they reflect on the gold object and so we think your scene is not empty
Remember how those settings are when you render in 2 minutes…
Finally, I would add a comment, something I am thinking from the beginning of your renders. The color between the objects do not always match. You have pink there, brown here, blue there, etc. You should try to create - in my opinion - a more artistic scene if you want to push your scene further. That said, you could try to harmonize the colors and the tones between the objects of the scene and/or create a more original mood with your lighting than plain blue (early “am”?, sunset?, daylight and spots?, etc) - the lighting could also help you to harmonize the tints between the objects of your scene. Good work! Push further 
