I think that you upgraded Q2A from 1.5.x to 1.6.2. And also, I think that you upgraded theme for 1.6. You may know it, security code was added in almost <form> at Q2A V1.6 for CSRF measures. Probably, cause of "Please click again to confirm" message is that security code is mismatch or COOKIE problem. I checked HTML of your site. Because security code exists in your login form, I seem that cause of problem is not that security code don't exist in your form.
It will be necessary for you to investigate PHP Error log. The detailed error cause of the security code should be recorded in error log. Source file is qa-include/qa-app-users.php (qa_check_form_security_code()).
I'm sorry if useless to solution to problem.