One time I was just exploring around what people built, Dry logged on, then like 3 minutes later, "Warning: Server restarting yadda yadda". Maybe there's too much stuff on the server
Also, playing around in the latest snapshot (13w10a).... Did they sneak in something that kills mob spawn rooms?
I made a new flat world and proceeded to build 3 slightly different grinders... Nothing is spawning in the dark rooms except a handful of bats. Occasionally 1 or 2 mobs will spawn, but that's it.
I know it shouldn't really matter, but I waited for night fall and bam, there's a million monsters all over the ground. So I torched it all up! Now nothing is spawning on the ground or in my spawn room day or night.
I don't get it!