AKo - lots of action - did I fold too easily?

[chadplusplus]

Party Poker 1/2 Hold'em (10 handed) converter

Preflop: Hero is BB with A[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/spade.gif[/img]. CO posts a blind of $1.
<font color="#666666">1 fold</font>, UTG+1 calls, <font color="#666666">1 fold</font>, <font color="#CC3333">MP1 raises</font>, MP2 calls, <font color="#666666">4 folds</font>, <font color="#CC3333">Hero 3-bets</font>, UTG+1 calls, MP1 calls, MP2 calls.

Flop: (13.50 SB) T[img]/images/graemlins/spade.gif[/img], 9[img]/images/graemlins/spade.gif[/img], 5[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
Hero checks, UTG+1 checks, <font color="#CC3333">MP1 bets</font>, <font color="#CC3333">MP2 raises</font>, Hero folds, UTG+1 calls, MP1 calls.

Turn: (9.75 BB) 3[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
UTG+1 checks, MP1 checks, <font color="#CC3333">MP2 bets</font>, UTG+1 calls, MP1 calls.

River: (12.75 BB) 5[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
UTG+1 checks, MP1 checks, MP2 checks.

Final Pot: 12.75 BB

This hand just has me confused... with a bet and and a raise, I thought for sure someone had hit the 10 or a set and I felt behind... this is my first posted hand... so any comments are welcome.