This easy bug crashes the server and corrupts the whole world

If you place a piston, a block of dirt on top, and then a tile on top of the block of dirt and you activate the piston, it will crash the server and corrupt the whole map. This might need to be fixed...especially since this spells doom for mc servers.

 

Kinda the same here. I placed a piston, which was linked to a redstone-activated button. I clicked it (for the automatic minecart dispenser I made this morning), and it gave me a cart. When I went to remove the piston, it killed my whole map and created a void then crash.

 

You can also place a upwards facing piston, block on top and a pressure plate to cause the same problem.
It can be fixed using MCEDIT and removing the offending blocks. IF you can find them...
Keep a temporary map up until this is addressed (Most likely by Notch) as it happens on vanilla, also.