Quote from neosatan
Found a bug: It's not possible to blacklist/whitelist items from ic2. Using build alpha 86 for 1.7.2.
Quote from homem_makako
I'm having the same problem. However not with Ic2 items, but with botania and blood magic items. I did notice the blocks show in the list, but items don't. For instance, the mystical flowers (botania) show normally, but the petals don't
Are these being showing in the creative inventory all-item search tab? Because I'm simply listing the items in there. However, if there are specific items that are missing (not everything from a mod) you can search for ".inv" and it will list everything in your inventory.