i finally found out where to find the last big poe! (well, for me, it was the last).
it was the one where you had to ride the horse on top of a cliff near the entrance to kakariko village. i wasted A LOT of arrows trying to kill it, and when i killed it, i couldn't get to the, um, the "little fireball with an evil smiley face" in time. urrggghhh

i finally got it bu looking at the othert way (opposite of the staircase to the village) and it appeared in a different spot and i owned it.

did something similar happen to you? did it take you ages to find this one?