Same problem as turueno and Wizard have here. It basically blacklists everything after some time, and runs around harvesting nothing. It blacklists for no apparent reason, also if the node couldn't be harvested because someone else used it, or if it's been attacked by a mob before the node could be harvested. I've tried putting settings to not ignore nodes with elites around, and ninja nodes, which gave no results whatsoever... Some minor problems as well - its wasting time a lot. Landing and standing for a few seconds, then standing for a few more after the node been harvested or standing for some reason when the node is been ninja harvested by someone else and getting mobs pulled. It all comes down to effectiveness, each second amounts to minutes and hours. If it's because of possible delay to wow server, for the actions not to fail, it better to for the HB to see the ping and act accordingly, i.e. if ping is low, interaction is faster, and visa versa.
P.S. not posting logs, because it doesn't say anything in there except "blacklisting node after 15 seconds" thing