I feelz like a derp. Well, why does it work with 1.7? And when I do put in the proper ingredients, the red glass appears and disappears in a second. But it appears...
We are playing a "fake"'1.7, so you can play with a 1.7 client, but you can't have any 1.7 crafting features.
You client belives you are on 1.7.2 but the server doesnt have any of the new items added to it. It appearing for a moment is a clientside thing, Not part of emc
considering forge has no stable 1.7 version and bukkit AND spigot are still using a dev version (as far as their latest post says) i doubt any server worth mentioning has a stable 1.7 out. if you would like to pm me the address of one id love to check it out tho.