is_author() seems not working

I know you you already replaced this plugin with Context Manager and offer support through twitter, but I just need the functions of Menu Rules and don’t have a Twitter-Account. So I hope you will read this.

The plugin works really nice, everything works as expected, except of is_author() combined with my author.php. It always highlights the news-section. To be completely sure it is actualy listed as author-page I var_dumped the is_author() tag on my author.php, with this result bool(true). Is there anything else I could try?

http://wordpress.org/extend/plugins/menu-rules/