Bukkit

Natural mob spawning is not happening on my server.  I believe it started happening after I used /halt for the first time. I have disabled halt, checked the /gamerule doMobSpawning is true, and the difficulty is on hard, yet no mobs are naturally spawning. Mobs still spawn out of spawners, and it seems pigmen spawn in the nether as well, but no hostile mobs spawn naturally in the overworld or nether (skeletons, creepers, blazes, etc.). This has rendered my server unplayable, and switching to a vanilla server rather than spigot re-enables natural spawning.