I created a basic prop of  a plate with a ring on it that goes on a wall (what Ill be using to hang a Kick bag in a scene). All was going great I even have it morphing to swivel the ring up and down  BUT......then comes rendering time.

If it is in a scene with another object loaded first things seem fine but if it is alone in a scene the entire object is obscured by a couple of large rectangular shadows once it is rendered, now Im thinking I have missed a step or something in setting up the material zones or something but am at a loss as to what.

Any help would be much appreciated, also any links to tutorials that show the full work-flow of creating a basic prop or object would be great.

Ive attched a pic if it helps.

Cheers Kurg