Problem is that Fire IE 0.4.5.3 is not allowing popups for sites in either the Firefox or Internet Explorer popup exception list. No matter what options are set the popup always opens in a new tab. Note that I am using Tab Mix Plus, but I have tried with it uninstalled with the same results. Also tried with a new FF profile with nothing but Fire IE installed and it does the same thing with any popup regardless of an exception or if the popup blocker is totally disabled or not – it just opens all popup windows in new tabs :-(.