How do you play this turn? (Very simple)

[TripleH68]

2/4 or 3/6. This is one of those situations that comes up often and seems very simple. Just want to make sure I play this correctly...

Hero is dealt AQo(no heart) in the CO. One limper. Hero raises. BB and limper call.

Flop(3 players/6.3SB):A /images/graemlins/heart.gif5 /images/graemlins/heart.gif4 /images/graemlins/spade.gif
Check,check,Hero bets,BB folds,limper calls.

Turn(2 players/4.1BB)9 /images/graemlins/heart.gif
Checked to Hero,???

<font color="blue">It seems too many times I bet here and get check-raised. Then I call to the showdown to see either two pair or a flush and roll my chips across the table. Checking through this turn seems very wrong. Folding in this spot can be difficult to do heads up even though the pot is not all that big. Any comments?</font>

What if the A is not of the flush suit, i.e.

2/4 or 3/6.

Hero is dealt AQo in the CO. One limper. Hero raises. BB and limper call.

Flop(3 players/6.3SB):A /images/graemlins/spade.gif5 /images/graemlins/heart.gif4 /images/graemlins/heart.gif
Check,check,Hero bets,BB folds,limper calls.

Turn(2 players/4.1BB)9 /images/graemlins/heart.gif
Checked to Hero,???