I'm having the same problem, which is to say that the text in the Post (or Page) is flush up against the left margin of the box, and changing padding or margin in
ATO > Body, Text and Links > Body Style
seems to change the box, but never moves the text relative to the box. I have tried putting either margin or padding in various places that supposedly change the text, and to no avail.
http://horanda.com/?p=49
shows a sample page. I want to move the text in from the edge of the box about 5 or so px.
Edit: in APO > Style POSTS and PAGES there is an entry for HEADLINE Box: Text
But there is no corresponding entry for BODY Box: Text
I am using Athahualpa 3.4.9 / WP 3.0.1