The wings on the onix oriental lamp seem to be wrong:

http://i.imgur.com/Vt9XSzA.png

It seems to break if you run Minecraft for a while, as if the individual rotor blades rotate at a very slightly different speed.

Thank you report.
This problem is probably caused by the lag of chunk reading.
(Lamp block wings were rotated by increasing the angle of the model for each Tick.
Because the two wings are individual processing the angle, synchronous operation is incomplete. )

In the next update, angle is commonly managed by TileEntity, perhaps the problem will not occur.

Ok, this is strange. I restarted Minecraft today and now it looks fine. No idea what happened...