My boomerang theme has been running just fine until I updated to WordPress 3.1 today. Now you can go to the portfolio section, but if you click to sort by any category you get:
Warning: Missing argument 2 for _post_format_link() in
/wp-includes/post.php on line 5172
my website is http://www.techcarellc.com/tcportfolio
Please let me know what is up. I have the latest version of the boomerang theme.