theme_epublish_format_pub() outputs entire page, not just content

theme_epublish_format_pub() returns:

return theme('page', "<div class=\"epublish\">$output</div>");

on line 824, but this will draw the entire page inside of itself. My fix was to elimate the theme() function:

return '<div class=\"epublish\">' . $output . '</div>';

...although I don't know if this is necessarily the right way to do it.