I would Check/Call flop.. Check minraise his turn bet.. Then lead River with a (half-timed down) delayed Push.. *This Line seems to be the Micro stakes kryptonite, they can't ever fold the minraise and find they are pot-committed come river!*

*With the info. of your opponent he's not afraid of the 6, since it's highly unlikely to be in your range (66 exception), he definitely has overpair and is questioning whether or not you really have the nine?*

With the line I stated above for this particular hand he will always pay you off, just because it looks so bluffy that you may have an overpair. He will look you up even if he knows by the river he is beat for metagame and future reference. i'm guessing QQ/KK since he is so stubborn?