Cannot login with Launchpad ID in Askubuntu

I just merge my launchpad ID and able to access the account without problem.

But I can't login Askubuntu (http://askubuntu.com/users/login) with the Launchpad ID.
Every time I tried with my Launchpad ID, it shows me the following message:

"Unable to log in with your OpenID provider:
Canceled "

I have search in Launchpad Answer Tracker and I found my problem little bit similar with [Question #150135]
I thought that I should ask this question in "Canonical SSO provider" instead of "Launchpad", but when I access the Question and Answer in "Canonical SSO provider" it keep return "Launchpad does not know where Canonical SSO provider tracks support requests", so I asked here.

Anyone can help me solve this log in problem?
Thanks in advance