I have noticed the same issue but I have always clicked on the actual web page THEN the tab to get the x to show up.. 5 months and no one has even acknowledged this problem regarding a fix, I have little hope it will be addressed anytime soon. I love Opera, it is my default browser, but this is VERY annoying behavior. Please look into this issue, there have been many enhancements made to Opera, maybe its time to squash a bug now.