I was having a lot of problems with my RL hub that came with my Monocog. the axle was slipping a lot in the dropouts, throwing off the alignment on my brakes. I finally figured out what was wrong: the axle and the cones are asymmetrical. I took the hub apart once to clean it up and accidentally replaced the axle incorrectly.
so if you have this hub (black shell, sealed bearings, hollow alu axle, disc tabs), remember that the axle is shorter on the left side and the shorter cone goes on the left. the left cone is probably 2mm narrower than the right one.