I'm sorry for your loss MsAqua, were they all housed in the same tank? Was the tank cleaned after each of their deaths or did you just stick another in? That might be why, if you are indeed doing that but it's okay. I suggest getting some Rubbing Alcohol from Wal-Mart to use to disinfect your tanks before using them as QT and disinfect them after the fish has left to a new tank or whatever. This will keep lingering diseases out so you could possibly have more if you wanted.
Just a thought though, but again, I'm sorry about poor Ezio!
Rembrandt II, Suiché
Leopards: 1:4 Hawkeye, Luna, Astrael, Dorian, Cullen
Gargoyle: Cloudjumper and Toothless