I think this is a really tough spot! A solid reg bets the turn:

That could really mean one of two things.
1)He flopped a set or two pair and cold called your flop bet and leads out when he hits the boat on the turn.

2) He was slowplaying some kind of overpair and is now protecting with a medicore redraw or something.

3) I also suppose it could be a blocking bet for a flopped straight who is scared of a flush, never thought of that.

The turn bet WOULD look like he is protecting an overpair or something if it wasnt so small. So we have to assume he wants action and is trying to induce a reraise here.

I would raise the turn, but grit my teeth when he shoves and then call and kick myself later.