When using render nodes, make sure that your plugin extensions are also added to each machine running a node.

In my case I was using Enhance C as well as other Digital Carver tools. I did an overnight render of several scenes and in the morning woke up to a horror show.

It took a while to figure out if there were shaders turning on/off/animated, we went through everything double checking... test rendered on the effected frames and they rendered great (however one processor test renders on the native machine). We re-rendered and watched in horror again as glitched results occurred again.

It wasn't until we watched the process that we realized the glitching was only occurring on the NODE rendered squares. We then went through the manual again, nothing was mentioned.

It wasn't until I opened up the Node folder that we saw the "extensions" folder and it clicked.
We test rendered again after applying the plug-ins and this rectified the problem.

So I hope this helps those venturing forth into Render Nodes, make sure you add your extensions to all your node machines.

:) Its the least I can do to post this so others may never feel the deadline pain I do now.

Carrara 7 Pro, Anime Studio Pro 8, Hexagon 2.5, Zbrush 4.6, trueSpace 7.6, and Corel Draw X3. Manga Studio 4EX, Open Canvas 5, WACOM Cintiq 12WX User