Problem making custom furnace

[Xenanthropy]

I'm having issues getting my custom furnace to work. It's strange, the gui and containers seem to work fine when I first place the block down, but as soon as I put items and fuel in, it spits out the items and fuel (except for one of each for some reason) and then it turns into a vanilla furnace while it smelts. I should also say that if I exit out of the furnaces inventory while it's smelting, then get back in (if it doesn't crash), the arrow and fuel indicators disappear, but the item still smelts. I copied most of the default minecraft code and just changed the names and stuff a bit, didn't really follow any furnace tutorials. Here is a video of what happens, along with my code for each class:

 

video:

 

Main class that initializes everything: http://pastebin.com/jvHXxkbF

 

EnderFurnace: http://pastebin.com/6dDG7PtX

 

TileEntityEnderFurnace: http://pastebin.com/YkiDBu7g

 

ContainerEnderFurnace: http://pastebin.com/zXXgAjpH

 

GuiEnderFurnace: http://pastebin.com/fqxVzyXN

 

GuiHandler: http://pastebin.com/9J4M7uPN