Hi guys. Thanks very much for the help. I've been busy with other things and haven't had time to sort things out.

I think it is a displacement map problem.

This is a mesh I had made several months ago then left it to do do other things, then returned to it just last week. Now I recall I did make a map in ZBrush back when and then started having problems when I put it on the poly but forgot about that in the interim.

I will examine the situation more closely when my schedule opens up, but wanted to thank you both for the help.

Tristan