Bukkit

version 1.31
Fixed an NPE in commands

Apparent Liquid height is based on what is next to the liquid.

IE. A fully surrounded water block at height 1 will look like a height 1 water block. A height 1 water block surrounded by air will look like a height 4 or 5. Its just the way minecraft renders liquids that are not attached to anything. Nothing can be done about it server side.

Setting the height of a fluid to something other then 0 will cause that liquid the be unable to be picked up with a bucket.

IE. if you dump a bucket of lava at a fluid height of 1 then that lava will remain at a height of 1 and you can not pick it back up with a bucket. Its just the way minecraft works.