Love this example mod. Nice design. I've just refactored my mod to incorporate some of your ideas. However, using your registration code in my mod, I noticed that none of the blocks I'm registering appear in my mod's custom creative tab. I finally figured out why. You're setting the creative tab on the block's ItemBlock (when you register the ItemBlock) when really I think you need to be setting it for the Block - inside the Block's constructor, for example. This is corroborated by the fact that if you call getCreativeTab for any ItemBlock, it goes and gets it from the Block.
Love this example mod. Nice design. I've just refactored my mod to incorporate some of your ideas. However, using your registration code in my mod, I noticed that none of the blocks I'm registering appear in my mod's custom creative tab. I finally figured out why. You're setting the creative tab on the block's ItemBlock (when you register the ItemBlock) when really I think you need to be setting it for the Block - inside the Block's constructor, for example. This is corroborated by the fact that if you call getCreativeTab for any ItemBlock, it goes and gets it from the Block.