Version: 1.2
When placing Cobblestone Melter and Cobblestone Generators they seem to duplicate and never remove themselves from the inventory until they are placed into a chest or other storage. Other blocks maybe affected by this.

Also the Melter has a Visual bug when the lava is bucketed out, the GUI still thinks there is still lava in it but it actually isn't there.

Fixed visual bug with c0f192e

Fixed block duplication glitch with ed2397c