Hey everyone, I just wanted to share my experience. Originally a raft or brim wasn't being generated for my model. After reading through this thread, I checked the layer view and dicovered that the first 5 layers or so of my model were blank. Even after adjusting the cutoff, the blank layers remained. What surprised me was when i looked at the gcode in Repetier Host. The layer view showed that the bottom layers were full. This appears to be a problem with Cura not recognising the bottom 5 layers of the model.