Drupal Themes by ThemeShark.com

What module are you using for fckeditor? The WYSIWYG API module (http://drupal.org/project/wysiwyg) creates a few issues when posting with the Filtered HTML input format. It uses css styles instead of tags to control the styling of the text, and because the Filtered HTML input type only permits the tags you allow (which can be configured by navigating to Administer » Site configuration » Input formats) all other tags get stripped. Choosing the Full HTML input type when creating your content would have better results.

Additionally, at the very top of each stylesheet (style1.css, style2.css, etc.) there's some code that's meant to reset certain elements and comform the styles in the browsers. Some of it, such as the 'strong' and 'em' tags, weren't redefined.

You may need to add this code to the bottom of stylesheet your using (style1.css, for example):

strong {
font-weight: bold;
}

em {
font-style: italic;
}