Angels keep dying...Help!!

[oneup]

I have a 210 fish only with a yellow tang, two puple tangs, a sohal tang, lunare wrasse, emperator angel, two maroon clownfish. I tried a regal angel and it ate great and then just diminished over a weekend and then died. I did the same thing with a Queen angel just this week that had the same results: eating great and then all of a suden dead. Fish are all from same reputable source and all my readings/levels are perfect. Any suggestions guys? I figure if my sohal and emperator are just fine, then why are my Angels dying?