I've installed your plugin with this other one http://wordpress.org/extend/plugins/custom-taxonomy-sort/ and they have a conflic. They both have approximately 8 functions with the same name. It would be good to customize the names in order to avoid this kind of problems.
The functions in conflict are:
update_termmeta_cache, add_term_meta, delete_term_meta, get_term_meta, update_term_meta, delete_term_meta_by_key, get_term_custom, get_term_custom_keys, get_term_custom_values
I renamed all of them in the other plugin and now both are working fine.