I'm using a PremiumPress theme, which may be why it's doing a couple of these things...
When using the WordPress button to login, it pops up the login screen for wordpress, then after login the popup window redirects to dashboard, or the users profile, and then does not close. It then only refreshes the post in question after I've manually closed the popup window.
If I'm already logged in to WordPress and try to post a comment, I am given an error "That email address is already registered with a Disqus account. Log in or enter another email." Essentially not allowing members to post comments unless they're already logged in, or must log in to a second system.
Because of the popup issue mentioned above, I've tried removing the custom wordpress image but there is no option to do so.