Aces against Kings on Ultimate Bet

8 player .05/.10 NL

I post the big blind of $.10. I have: Kd Kc

Pre-flop:
player in middle position raises to $.20. Small blind calls. I re-raise to $.45. Middle Position re-raises to $1.95. Small blind fold. I re-raise to $3.45. Middle position re-raises to $10.55. I go all-in for $5. Middle position is returned $5.55 (uncalled).

(board: 7c 8h 9c As 5d):

Showdown:
Middle position shows Ac Ah.
Middle position has Ac Ah 8h 9c As: three aces.

I show Kd Kc.
I have Kd Kc 8h 9c As: a pair of kings.

Summary:
$.50 is raked from a pot of $10.20.
Middle position wins $9.70 with three aces.

Bad enough to be up against aces... and of course there is an Ace on the board instead of a king!