[capidamonte]

Thanks for that link. I'm now integrating that into my macro library for use with floated images in some of my book sections -- this makes them look good when displayed in browsers and ebook readers that use XHTML engines (like Calibre's).

EDIT: Actually the link at the top of that page proved even simpler: add overflow:auto or overflow:hidden to your outer div. overflow:auto was adding side-scrollbars, but :hidden did the trick.