Firefox 2.0.0.20 is the last ever release for Mac OSX 10.3.9 and earlier versions. Which version do you have?

hi...thanks for reply:

i have iMac: system 10.5,8

so what do i dO =? thank you.

See http://kb.mozillazine.org/Installing_Firefox#Mac_OS_X ..... Download a new copy of the Firefox program: http://www.mozilla.com/firefox/all.html Trash the current Firefox application to do a clean reinstall. Install the new version that you have downloaded.

Your profile data is stored elsewhere in the Firefox Profile Folder, so you won't lose your bookmarks and other personal data.

thank you. i will try this. rosa