Tristor reports that it was possible to spoof the browser's secure-site indicators (the lock icon, the site name in the URL field, the gold URL field background in Firefox) by first loading the target secure site in a pop-up window, then changing its location to a different site.
If the user has turned on the "Entering secure site" modal warning dialog then the window location can be changed while that dialog is displayed and the secure-browsing indicators from the original site will remain.
These dialogs are turned off by default in Firefox, and most Suite users click the checkbox to turn them off.
Turn off the "Entering encrypted site" warning dialog if you have not already.