I have noticed a strange thing:
If you buff yourself in town and then change map server (warp or run somewhere) then server tracks 2 sets of your buffs in memory - the ones you had in town and those you currently have in fields. If you happen to die (you should lose all buffs) and respawn in town - you'll have you town buffs (agi bless) back, even if you was in fields for an extended time.