Well, with the All-In he's going to get all the cards he wants once you call, so that's to your disadvantage if he's chasing a low-straight. The A26 is potentially scary - with someone like that he might have called your preflop with K3s or 45s or such silliness.

Anyway, I'd say call him and hope he busts himself chasing a straight. If calling him is going to kill your stack, that'd be tougher.