While testing the Slayer class I was playing around with high level powers and I could not get the Astral Seed power to work. I'm not good on the event hooking, but I'm guessing that its just not triggering upon death - the casting looks good.
As a separate item:
While poking around in the code and reading up online about the hooks into various spells/powers I saw that the name of the script to be executed is actually 17 characters long instead of 16. I *think* that means, since you can't create a script name longer than 16 characters, that the hook isn't going to work, but I haven't tested it myself.
Code:
// Persistant World death hooks
ExecuteScript("prc_pw_astralseed", oPC);
if(GetPRCSwitch(PRC_PW_DEATH_TRACKING) && GetIsPC(oPC))
SetPersistantLocalInt(oPC, "persist_dead", FALSE);
Assuming that it won't work, the simple fix for this would be to revise the hook to "prc_pw_astralsed" or the like.