I voted sometimes. And I have some recent examples to back it.

A couple weekends ago we were in Tahoe and went to breakfast at a little place. I ordered an omelet with mushrooms, spinach and avocado. The omelet was HUGE and I begin eating around the outside edge. Once I got toward the middle I discovered there was onions instead of avocado inside. YUCK!! I can't stand onions so I sent it back and they made me the correct food. Luckily Bruce didn't have a large meal so he helped me eat it since I was almost full from the outside edge of the first one.

Another example was the other night we went to Applebee's and I got my favorite chicken meal (Bruce got the same thing). When they brought it to the table there was a large black hair with grey at the end right there on the chicken. Since I could not identify it as mine, Bruce's or any of our animals I sent it back. The manager was at our table before the waitress even got the food back to the kitchen. They took my meal off the bill and made me another one (although I think they just removed the piece of chicken and remade that because the potatoes were cold in spots).

But an example of when I might not send something back is when I order steak. I usually like my steak cooked so it is either not pink at all or a very light pink in the middle. Sometimes it will be a little more pink/red than I'd like, but I won't send it back. It just depends on how it tastes really.