I have noticed when I attempt to login with more that one social account that has the same email address, we get the following on twitter logins. If the user comes in on twitter, and only uses twitter to access the site, then it works. In my case, I logged in as twitter ok, logged out, logged in as google, logged out, and attempted to log in with twitter again and get the following error. At the point where you login with another social account, you can no longer login any longer with your twitter login.
Any reason why only Twitter causes this behavior?