FYI, I have the same problem with Twitter.
It goes through the whole process but ends up not logging in.
I will keep looking a while and contact you if I don't make progress.

It is just that there are not that many parameters that I can 'mess up' in your extension and I don't think misconfiguration is the issue. I followed your video tutorials (Google + is a bit outdated though) so this should be fine also (I would get errors otherwise anyway).

Therefore it seems to be a site issue but I just can't put my finger on it...

Thank you for the fast responses. I will keep you posted.