Matt-
I got mine in the same time as yours. It was racing around the tank for a few days, and wouldn't touch any food. It would pick at the live rock, overflows, etc. James mentioned to me at the MARS meeting that his would go crazy for cyclopeze, but nothing else. I tried using it as well and mine ate it.
I then started adding brine shrimp, Formula 2 Flake, dried Seaweed, etc. to the mix and it now eats everything. Mine looks great and is now running with the other tangs. It's in a 135.
Marc