I am not at all a Blender expert, but I am using it to try and make a simple christmas card image. For this I have used the lsystem plugin to create something that looks like a christmas tree, and am now trying to render some reflective sphere ornaments. But there are errors in the sphere rendering where the tree reflects on the sphere surface, they look like little squares (look in hte upper right corner of the red sphere in the included image). Is there anything I can do to remove these squares from the reflection? http://web.mac.com/danbumbarger/treeandspheres.jpg
I may not be correct, but I think that you will need to add a subsurf modifier to the spheres.
sorry… kept looking, but can’t seem to find what’s wrong 
you have any larger image?