This bug occurs when navigating thru months after reading an article.
[b]Sympton: [/b]Each time clicking previous month/next month, the CAPTCHA image page is reloaded.
[b]Cause: [/b]After reading an article,we click the cross on the top right corner to *close* the article panel. But as a mater of fact, the panel is not literally *closed* and disposed,it is just hidden from the user.
[b]Fixie: [/b] Hide the article panel and set the innerHTML of the panel to String.Empty.