Issue on Validating the Registration

I am facing a problem with user registration. An user registers by putting all the required fields and he gets a page saying that 'Registration is successfull'. A validation email is also been send to him. If he tries to login without activation, XWiki logs him in and gives a message 'Your account is not yet active, because your email has not yet been confirmed.'. He goes back to his mail box, copies the activation link and paste it on the same window. But the page remains the same and doesn't allow the user to activate his account. He need to open a new browser or logout to activate his account and login to XWiki. This looks like a bug. Any comments on this ? I am using XE 1.6.