Board Thread:Questions and Answers/@comment-14611846-20130806002209/@comment-13037480-20130806032621

Nether ores have no height level for them to be at. You, my friend, are just very unlucky. What I advise, try setting up a hardened drill miner (if you can't get Galgadorian) with a shield addon equipped along with a liquid sensor, railer, and of course, storage. If you're not going to be near it all the time, it would be best to also equip a chunk loader.

Hope this helps you, cause I myself know how irritating these ores can be.