Fatal error: Cannot redeclare inline_edit_term_row() (previously declared in /Users/everett/Sites/wordpress3/html/wp-content/plugins/custom-taxonomies/backwards_compatibility.php:77) in /path/to/wordpress3/html/wp-admin/includes/template.php on line 77
Gotta fix that.. maybe it's only showing up in certain versions of WP, but even when I remove that file and comment out the include statement, you have unhandled PHP notices. If I had a nickel for every plugin I found that did not handle PHP notices correctly, I'd have a small fortune: the repo is FULL of them, and I won't use any of them because it means your code has problems. You MUST turn on PHP notices when developing plugins.
Looks like you're using a deprecated function call to wp_specialchars in 3 files:
Use esc_html() instead.