isolation to middle pair ... do i call the donk?

Don't have specific reads, but I just remember villian had a decently high vpip, but pretty standard for 1-2 6max tables.

Comments on all streets appreciated ... can I call this river-donk?

Party Poker 1/2 Hold'em (6 max, 5 handed) converter

Preflop: Hero is Button with A[img]/images/graemlins/club.gif[/img], 9[img]/images/graemlins/spade.gif[/img].
UTG calls, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises</font>, <font color="#666666">1 fold</font>, BB calls, UTG calls.

Flop: (6.50 SB) 6[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/diamond.gif[/img], J[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, UTG checks, <font color="#CC3333">Hero bets</font>, BB folds, UTG calls.

Turn: (4.25 BB) 2[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
UTG checks, <font color="#CC3333">Hero bets</font>, UTG calls.

River: (6.25 BB) 4[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">UTG bets</font>, Hero calls.

Final Pot: 8.25 BB