[arock]

Problem; Some surface materials do not render leaving a white plane instead.

[tom]

Problem; Some posts do not reside in correct sections leaving a pollution instead.

[JamesColeman]

Problem; Some posts do not reside in correct sections leaving a pollution instead.

Stuck between arock and a hard place.

[Bubbaloo]

He has probably checked the matte/shadow option.

[JamesColeman]

Problem; Some surface materials do not render leaving a white plane instead.

He has probably checked the matte/shadow option.

Thinking about it, I've also seen this behaviour recently with a client who didn't have the most recent version. Make sure you have 2.7.2