The interface of the alloy furnace isnt opening if you try to. This is a very severe bug as the Alloy furnace is commonly used for most of the RedPower stuff.
Furthermore, alot of Machines with GUI arent opening properly : Tested so far : 1. Alloy Furnace 2. Project Table Aswell, you get crashes of client when trying to NEI certain items crafting recipes : Tested so far : 1. Macerator 2. Personal Safe 3. Extractor 4. Compressor