The "Water Glitch" when you take water on the top layer of the water when there is a 2 deep hole of water is there again... If you do not understand what I mean, do the steps in Minecraft. (Done on a minecraft 1.7.4 Server)
1. Make a hole (3x3x2 recommended for trial purposes)
2. Fill it to the brim with water
3. Take a bucket and take water off the TOP layer of the water.
The water should be glitching in the way you have to put a block underneath to make the water revert to normal.