Conflicting code in the authenticate filter?

Thanks @iandunn for telling me about this plugin, it is exactly what I’m looking for. However, I did run into a slight issue after I installed it. Things work as desired for the non-administrators, they just log in as normal without the authenticator field coming up, but for the administrators I have a conflict once the authentication code is submitted. I built a custom login page and workflow for the site. I have a filter setup that fires during the authenticate filter as well, so when I submit the authentication code I get redirected to our custom login page with the error message that normally comes up for a user when they try to login without filling in their password. Any thoughts on a way to work around this?