PLA Layer Separation Diagnosis

I've got a Makerbot Replicator 2, using SainSmart 1.75 mm PLA. I've got pretty bad layer separation. When this happens, I end up with a half finished part and a spaghetti mess. I'm trying to diagnose the problem.

I know that the main causes are either extruder temperature or filament binding. I run at 230 degC. When I bump up to 235 I get the same thing. So I don't think that's the problem. I am concerned about filament binding though. I did have to unravel about 12 feet of filament and rewind it. I'm curious though, if the filament did bind then it would stop flowing all together, right? It wouldn't stop, unbind and then restart would it?

I was having a similar issue with my Z18. I found that the room temperature to be a big part of my problem. My printer was directly underneath an AC vent. Moved the printer and heated the chamber to a toasty 30C. It's still not where I want it, but its a start.