c/o was an easy call, its the SB that poses a slight worry. Best case scenario is that he fancies his average hand against a desperate players all-in, so wants to single him out. Need a bit more history to tell if its as cut-and-dried as that though.
Really, your only worried about a high PP, and even so, your a coin flip at worst unless your against bullets.
Conclusion? Shove em in. A fold here shows a player attempting to limp into the cash, not make the final table. Play it to win.