Unknown Mental Ray Error

hello all

so im using maya 8.5 and im trying to do a single frame render using mental ray. last week this same file was rendering.

now im getting the error message
// Error: (Mayatomr) : unexpected internal exception during scene rendering, please report //
// Error: (Mayatomr) : unexpected internal exception during scene cleanup, please report //

to try and "fix" the problem I've:
-deleted the prefs
-deleted unused shaders
-optimized my scene
-went into the outliner and deleted all empty group nodes and condesed the ones i have
-deleted history on everything

yes, the mental ray plugin is loaded.
im all out of ideas, any suggestions. even the simplest most basic thing may help

thanks in advance
mike

Its a fatal bug you should contact autodesk. (however since maya 2008 is out they will just probbaly telol you to upgrade)

You could try to export all and impirt it into a new scene. But most likely theres a something corrupt in the geometry itself.