roger64: The epub you posted produces exactly the sort of ugly variation in line spacing that must be avoided. It does this in both ADE and calibre's reader, because that's what's specified in the css standard. The sup tag needs to be modified in the css to reduce the line-height in order to prevent this. See my
earlier post for an example of what superscripts
should look like. Jellby's method and mine are essentially the same, though mine allows a bit more control over vertical positioning.