<A target="_blank" href="https://www-304.ibm.com/support/docview.wss?uid=swg21504751">This Technote says Firefox 5 is supported with iNotes versions 8.5.3</A> and Interim Fix 1 for iNotes 8.5.2 Fix Pack 3. <A target="_blank" href="http://www.maximumpc.com/article/news/firefox_6_track_launch_tuesday">Firefox 6 is due to be released next week</A>, there's no word on when it will be supported.