In reply to wild_nomad:
Sounds like the sheath has slipped a little towards one end, usually a result of favouring one end of the rope over the other. No big deal, you can either ignore it, try to redistribute it back up the rope (and switch ends more regularly from then on), or, if it gets really bad, cut off the heat-sealed end, milk the excess sheath off the end, cut it off and reseal.