Should I have check/called this river?

[FreakDaddy]

Villian is 21/4/3 I have over 250 hands on him, but I don't really recall his play and he just recently sat at table. My feeling was that he had 55. What player with these stats is going to call that flop bet, check when the board gets paired and then call when I set him all in? Is it just 50/50? Either he has flush or I'm beat to 55, I don't think he's calling Jx either. What do you think, and should I have raised the flop more?

Party Poker No-Limit Hold'em, $ Hero (8 handed) FTR converter on zerodivide.cx

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

UTG ($21.85)
UTG+1 ($48.05)
MP1 ($23.86)
MP2 ($7.25)
<font color="#C00000">CO ($24.55)</font>
Button ($29.90)
SB ($44.55)
<font color="#C00000">Hero ($36.18)</font>

Preflop: Hero is BB with 2[img]/images/graemlins/spade.gif[/img], 2[img]/images/graemlins/diamond.gif[/img]. SB posts a blind of $0.10.
<font color="#666666">4 folds</font>, CO calls $0.25, Button calls $0.25, <font color="#CC3333">SB (poster) raises to $0.65</font>, Hero calls $0.50, CO calls $0.50, Button calls $0.50.

Flop: ($3) J[img]/images/graemlins/heart.gif[/img], 2[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">SB bets $1</font>, <font color="#CC3333">Hero raises to $4</font>, CO calls $4, Button folds, SB folds.

Turn: ($12) J[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, CO checks.

River: ($12) T[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $20</font>, CO calls $19.80 (All-In).

Final Pot: $51.80