The address field should always show the correct address for the page that is loaded. If a page can cause Opera to display certain dialogs relating to a target site, the dialog may in some cases cause Opera to display the target site’s address instead of the correct address. This can allow an attacking site to mimic a target site. This issue will not affect the security information dialogs, which will continue to show the correct information.
Opera Software has released Opera 11.62, where this issue has been fixed.