Can you list your plugins? Actually, I'd recommend that anyone posting here list their plugins if they are experiencing trouble. Because, it may not be bukkit causing the trouble, it might be a common plugin that everyone has that is causing the issue. And, knowing what you have running might help. Keep the list of plugins horizontal instead of vertical if you can, e.g. a comma separated list like; plugin a v1.4, plugin b v1.6, plugin c v1.0, plugin d v1.2. That will save viewing space in the forum. Knowing the versions of each plugin could be useful for us as well since it may be that you have an out of date plugin that has fixed its own performance issues in an updated version, for example.