can ribbo fold mid set?

[jeffman]

PokerStars Pot-Limit Omaha High, $2 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

BB ($222.65)
UTG ($210.90)
MP ($1062.30)
CO ($121.45)
Button ($106.30)
SB ($274.90)

UTG calls $2, MP calls $2, <font color="#666666">2 folds</font>, SB completes, BB checks.

Flop: ($8) 9[img]/images/graemlins/diamond.gif[/img], 5[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, BB checks, UTG checks, <font color="#CC3333">MP bets $6</font>, <font color="#CC3333">SB raises to $25.6</font>, BB folds, UTG folds, MP calls $19.60.

Turn: ($59.20) K[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets $56.3</font>, MP calls $56.30.

River: ($171.80) 3[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, <font color="#CC3333">MP bets $100</font>, SB calls $100.

Final Pot: $371.80


MP showed [3 [img]/images/graemlins/diamond.gif[/img] 2 [img]/images/graemlins/club.gif[/img] A [img]/images/graemlins/heart.gif[/img] 2 [img]/images/graemlins/heart.gif[/img]] and won ($368.80) with a straight, Ace to Five
SB mucked [9 [img]/images/graemlins/spade.gif[/img] 7 [img]/images/graemlins/heart.gif[/img] 9 [img]/images/graemlins/heart.gif[/img] 5 [img]/images/graemlins/spade.gif[/img]]

I was loafing around recently looking at 1/2 and i saw ribs play this hand. Is it usually good to pay off 100 dollars on river with a hand this weak.
Thanks for the imput