Massive server lag in 1.6.1

SMP is highly unstable with multiple users on. Tick will jump wildly depending on the activities other users are doing.

Being in the same chunk as a village is almost impossible as the lag spikes through the roof. 300+ tick is not uncommon. Other activites I'm yet to discover are causing these issues. Never experienced any of this in 1.5.2.

And just for reference, had 300+ tick in 1.5.2 when a user built a village breeder and there were over 180 villagers. Same lag in 1.6.1 just from simply ENTERING a village chunk(not same one with 180).