I had done that several times and always get the following message.
Your email could not be confirmed. Either you have already confirmed it or the link that you clicked is incorrect. If you have already confirmed your account, please sign in by providing your username and password. Otherwise, please contact a moderator or an administrator for further assistance.
Might have something tangentially related to your signature privileges. I've restored your privs from earlier, keep the sig in check if you would. Also, try the solution I recommended earlier now. Let me know if it still doesn't work.