I am needing a way for my custom module to perform certain tasks upon a user role change. So I've been trying to use the following api hooks:

hook_user_role_insert
hook_user_update
hook_user_role_delete

However, they seem to not work. Am I missing something? Im assuming that like the other api hooks, these are called upon the user role changes, but they are definitely not being fired off for me(cache cleared).