$25 PL: When the river changes the best hand

[se2schul]

In this hand I make my nut flush and nut low with counterfit protection on the turn. I've built a big pot and then the board pairs on the river. I bet again on the final street, but I'm not sure that it was correct to do so. No reads.

When the river changes the nuts, should I let go of a hand?

Party Poker (7 handed) converter

Preflop: Hero is CO with 3[img]/images/graemlins/heart.gif[/img], 2[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/heart.gif[/img].

4 of us see the flop with no raises

Flop: 6[img]/images/graemlins/spade.gif[/img], 5[img]/images/graemlins/heart.gif[/img], T[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>

I bet pot and get 1 caller.

Turn: 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
UTG checks.

I bet pot again with 1 caller

River: 6[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>

I pot it again he calls and I quarter him.
Should I have checked/called the river?