Sugar Canes can be placed underwater

How did it happened: I placed blocks under water to my underwater house, then I placed accidantly a sugar cane, and it stayed under water.

How can it be used: I did not tested whether or not they grow (I think they are not growing...) but players can place them underwater and they can get air from it so they are not drowing.

What I exepted to happen: I tought that if I place a sugar cane underwater it is place it for a sec, then it falls down because of the water.

What happened: It is just stayed underwater, as you can see the picture.
This is works on: Bukkit servers, single player (vanila minecraft, no modded) and I did not tested it on vanilla servers. Works on 1.4.4, 1.4.5, and it is works in adventure, survival, and creative mode.

Useful for: Breath under water

In addition: It creates a lot of lag, and fps is dorrping to 2 from 40 if you place them under water.

Screenshots: They are from a bukkit server, and my single player world.

Reproduce the problem: There is no way to "reproduce" this problem is only can be fixed by a litle programming......