When one's breaks any AA block with TE, TE doesn't get destroyed and stays where the block used to be. Block at new location doesn't work (you even can't open it's GUI). Placing any other block with TE in it at the old location causes a crash about impossible cast of TileEntities.

Forge: 2072
Mod version: r61

What? That doesn't happen to me O_o

Which blocks does it happen with?
Try using the recommended version and see if the bug persists.

can you post the latest log and/or a modlist?

It happens with any block I think (Coal generator, Double Crasher, Double Furnace, Atomic Reconstructor confirmed).
Here's the crashlog (player tried to place ExUtil thing): http://pastebin.com/gTjGNxJ2