When I do a post and I don't want to preview it, the submit button is on the left and the cancel button is to the right of it.
If I do want to preview it, on the top there is a "cancel message" button on the left and an "edit message" button on the right but no submit button. Now it's on the bottom.
Twice today I hit the cancel button after previewing a message and I'm thinking that there used to be a submit button where the cancel button now is?