Replicator 2X Dual Extrusion Problem

I know that Dual Extrusion is a bit picky at times, but we have yet to get a successful dual-print that looks good...

The most recent failure was when I took the pre-loaded chain model that comes with the printer SD chip and cut it up a bit so that every other link would print with a different color to the one next to it.


I can post a picture of it, but I know as a fact that the model will print with one extruder on our Replicator 2..

Here is what it I came back to the lab to find yesterday:

Attachment 54
Attachment 55

Yes, that blob of red is a solid chunk of plastic that the printer just spit out.