What happens when your nozzle doesn't quite sit against the PTFE Insulator (The white stuff in the image)? It just clogs up the nozzle, and blocks the extruder.

You can tell by the tell-tale blob or ridge (See image) If you can manage to get the filament out without too much trouble. 

I ordered a new nozzle (V5) plus heaterblock plus insulator from reprapworld and so far it works great. But still, the PTFE remains my number one point of failure. 
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