Recipe of subject uses only iridium found in dungeon chests but not ingots made from ore. I suggest to add minetweaker recipe to use iridium (ingots?) made from regular ore (from void miner etc).
As the others here have states, the Iridium Ore =/= Iridium Ingot, per design. IC2 adds the option to create Iridium (If you have at least one already) through the use of UU-Matter and using that to replicate. That is the intended way to "get more" than just going dungeon-skipping