With Firefox 4, I get a message "additional plug ins required" when trying to use TD Ameritrade's Command Center. Even they don't know what additional plug in will make it work. It worked fine on Firefox 3.6
TD Ameritrade's Tech Support said that Firefox 4.0 will not work with their Command Center. Keep getting an error message "additional plugins required" but nobody knows what it needs. Firefox 3.6 and all the earlier versions worked just fine (better than Safari). Command Center is a web based stock trading tool that features streaming real time charts, Level 2 quotes, Last Sale lists, and order entry.