Always auto-bet this?

[Benman]

When I'm the lone pre-flop raiser, have only one or two opponents on the flop, and it is checked to me, I nearly always auto-bet the flop. Is this a terribly bad habit? Sure, I get check-raised some, but I think I make up for it with my steals. Isn't this line the default, or am I way off base?

Follow up question: if I'm wrong, and I shouldn't always bet in this position, when not to bet? With my worst hands? Something tells me this may be totally wrong, in that I should be betting my good and bad hands, but not some category of mediocre hands?