I like the idea of this mod, but I can't confirm the world generation works (using v0.7) - I can see the iridium ore block (and the crushed and centrifuged forms of the ore) in NEI, so I'm pretty sure the mod is installed properly, but I used a mining laser to dig tunnel mines at layers 12-14 around 800-1000 blocks long, first in unexplored territory of a single-player survival world that was started without it installed, then in a fresh creative-mode world, and I didn't see a single iridium ore block as I went (and I use 128x textures from bdcraft.net, which means the 16x texture would have been easy to notice). If I'm interpreting the decompiled code correctly (I might not be, since I've never tried to write a mod myself), it generates 25 size-3 clusters per chunk (for the overworld, I don't have mining world installed), distributed between layers 0 and 20, so I should have seen a few of them in my tunnel mines.