Managed to find a much better OpenID plugin than the one I was using. This one addresses the two main problems I had with the previous plugin. Previously it was necessary to modify theme files in order to work, so it means I’ll have difficulty upgrading, or even just using another theme. Also the previous plugin did not create WP users, so I couldn’t use the post-levels effectively.
Another secondary issue was that the previous plugin included an OpenID server, which conflicts with the one I had already setup. This new one is a pure consumer, so I am able to use back the original server, which allows me to login during the redirect instead of simply prompting ‘I must be logged in at WP to use my OpenID’.
However this plugin seems to be still in its early stages (v0.85), and I had problems activating it initially. I had to deactivate and activate it again before it installs successfully. There’s also a border around the OpenID logo if you use particular themes. Hopefully functionality-wise it’ll work just as fine as previously. Time will tell.
Note to existing OpenID users: To authenticate yourself now, you will need to enter your full OpenID URL. For LJ users that is “username.livejournal.com” without the quotes.