trying to download new version; telling me I don't have sufficient permission to access certain features so won't go in applications folder.
I'm on an older MAC operating system 10.4.11 - when I try to drag the new Firefox icon into the Applications folder I get that prompt and it won't go. Have no idea what it means.
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.