My last jib furler issue was due to a halyard wrap. Not the jib halyard, as that has a fairlead on the front of the mast down about 6" from the sheave. The wrap was the spinnaker halyard, which I'd led to the bow pulpit. It had gotten a bit slack and caught the upper swivel. I was able to resolve the issue at the time (a bit hairy..) by unrolling the jib then tightening the spinnaker halyard. Jib then furled properly. I now keep the spinnaker halyard on a ring on the front of the mast.
Something let go with a 'Bang!? I'd be really curious to find out what it was.