ok,
i have done what ya said and it still doesn't work so i think it is a problem with MR. i also re-installed MAYA but it still wont render the scene. It will either render it without any IBL or final gather (and so on) or it will start rendering out but then it will suddenly stop and i will be left with an .iff file.

Here are my rendering settings if it helps.

Edit: ive also tried it with the software renderer and it worked.