I have 3 WordPress sites at version 3.0.4 that produce the same error when I click the authenticate link. Two sites were upgraded to 3.0.4 and the plugin installed afterwards. The third site is a clean 3.0.4 install. In all cases, I'm using the 1.4.1 plugin.
I have 3 other sites that had the plugin installed first then upgraded to 3.0.4 and the plugin works fine on those sites.
Has anyone else run into this and if so, is there a resolution?