Support for Firefox 4 is introduced in Interim Fix 401.8HF6 for iNotes 8.5.2 Fix Pack 2, which is now available for download from Fix Central. iNotes 8.5.2 Fix Pack 3 will also provide Firefox 4 support. This interim fix can be applied on a Domino server running 8.5.2 Fix Pack 2 or a Domino server running 8.5.2 Fix Pack 2 with a Domino hotfix. If you are running 8.5.2 Fix Pack 2 with an iNotes hotfix, please contact IBM Support to request a new iNotes hotfix that combines iNotes IF 401.8HF6 with your existing iNotes hotfix.
The information above is fron TN 147006