I'm using WP-members with a few customisations, but have had it fully set up and working correctly in a dev environment. When I move it to the live environment (on the same server) the User profile buttons ('Edit my information' and 'Change password') still show up, but stop working.
I have the exact same settings and plugins on the live site as the dev site, and the live site was created by importing the files and database from the dev site directly. Both are running the latest version of WordPress.
I have disabled all other plugins to test, and have also completely removed WP-members and set it up again from scratch on the live site with the same results.