Mis-use of a blocking bet?

[Matt R.]

Is my river bet here a bad application of a blocking bet? I don't think I could really bet any more due to my stack size, and I didn't want to be bluffed out of the pot once the 3rd club hit if he wasn't on the flush draw. Apparently I was getting bluffed out either way. Any ideas on how to play the hand differently?

Party Poker No-Limit Hold'em Tourney, Big Blind is t50 (10 handed) converter

saw flop|<font color="#C00000">saw showdown</font>

SB (t5185)
BB (t2955)
UTG (t10040)
UTG+1 (t1178)
Hero (t2225)
MP1 (t1250)
MP2 (t3940)
MP3 (t1595)
CO (t900)
Button (t685)

Preflop: Hero is UTG+2 with 9[img]/images/graemlins/diamond.gif[/img], 9[img]/images/graemlins/heart.gif[/img].
<font color="#666666">2 folds</font>, <font color="#CC3333">Hero raises to t150</font>, <font color="#666666">1 fold</font>, MP2 calls t150, <font color="#666666">4 folds</font>, BB calls t100.

Flop: (t475) 8[img]/images/graemlins/spade.gif[/img], J[img]/images/graemlins/club.gif[/img], 7[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, <font color="#CC3333">Hero bets t275</font>, MP2 calls t275, BB folds.

Turn: (t1025) 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, MP2 checks.

River: (t1025) 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets t350</font>, <font color="#CC3333">MP2 raises to t1200</font>, Hero folds.

Final Pot: t2575

Results in white below: <font color="#FFFFFF">
MP2 has Ac Td (one pair, sevens).
Outcome: MP2 wins t2575. </font>