I use Norton Internet Security for my computers. I also use Firefox rather than Internet Explorer. I recently attempted using the newest version of Firefox and discovered that I cannot use the autofill feature of Norton to fill in logins. I retreated to 3.5.8 version and all is well. I cannot upgrade unless this issue is resolved. Also I am unable to open certain Adobe Acrobat files from within the Firefox program as I am informed that the latest version of the Reader is unable to open anything. I know this is an add on problem but am asking what version of Reader is supported in Firefox so that I can reinstall a previous version.