Bukkit/CraftBukkit — pull request #526 by Qala (2011-11-02 22:05:49+00:00)
Title: Fixed player only dropping XP on first death

In EntityLiving, deathTicks was preserved across Player deaths and even saved to player.dat (as "DeathTime").
This caused (this.deathTicks == 20) to only fire when the player dies for the first time.