Symantec need to update their Firefox add-ons so that they are compatible with Firefox 4. They have indicated that for Norton 360 they plan to release an update to Norton 360 to support Firefox 4 in early May - http://us.norton.com/support/kb/web_view.jsp?wv_type=public_web&docurl=20100720113635EN&ln=en_US

I do not know about the time scale for updates for other Norton products. Pending the update by Symantec, if you want to use the Norton add-ons you will need to downgrade to Firefox 3.6.

To downgrade to Firefox 3.6 first uninstall Firefox 4, but do not select the option to "Remove my Firefox personal data". If you select that option it will delete your bookmarks, passwords and other user data.

You can then install the latest version of Firefox 3.6 available from http://www.mozilla.com/en-US/firefox/all-older.html - it will automatically use your current bookmarks, passwords etc.

To avoid possible problems with downgrading, I recommend going to your profile folder and deleting the following files if they exist - extensions.cache, extensions.rdf, extensions.ini, extensions.sqlite and localstore.rdf. Deleting these files will force Firefox to rebuild the list of installed extensions, checking their compatibility, and reset toolbar customizations.

For details of how to find your profile folder see https://support.mozilla.com/kb/Profiles

I think that you have downloaded/installed yahoo firefox 4.0, the latest, right? If so, do this: download and install older version 3.6.16 http://www.mozilla.com/en-US/firefox/all-older.html It will overwrite your 4.0, and you will get back Norton tool. I just had the same problem. I didn't uninstall 4.0, just 3.6.16 installed over it As simple as that.

Here's the answer from Norton:

http://community.norton.com/t5/Norton-360/Norton-compatibility-with-IE9-and-FF4/td-p/420024

03-22-2011 05:10 PM

Our developers continue to fix compatibility issues between our Norton products and the latest browser releases, and we have some updates on the status. We plan to release an update for NIS/NAV 18.5 and Norton 360 v5 in early May that will address the problems found in both Internet Explorer 9 and FireFox 4. We’re still working on this patch, and testing it thoroughly. Thank for all your help in identifying the issues between the products; that has certainly helped us in resolving these compatibility issues.

We will be releasing patches for a few older versions of NIS/NAV and Norton 360, but these patches will take longer to test and release. We recommend that you update to the latest version. As always, updating to the latest version of these products is free with a valid subscription to the product. http://updatecenter.norton.com

Tony Weiss Norton Forums Global Community Manager Symantec Corporation

I have uninstaled firefox 4 and instaled firefox 3.3.16 but it wont load up, i have got the icon on my desktop but when i click it nothing happens :(

hi bobcat, I have uninstaled firefox 4 and instaled firefox 3.3.16 but it wont load up, i have got the icon on my desktop but when i click it nothing happens :(

you did not have to uninstall 4.0, because Firefox 3.6.16 will overwrite it. You just had to simply download/install 3.6.16 version.

Now, here's the solution. Now install 4.0 again, don't uninstall 3.6.16, as 4.0 will overwrite it. and go there http://community.norton.com/t5/Norton-360/The-Firefox-4-compatibility-hotfix-is-now-available/td-p/428898 The Firefox 4 compatibility hotfix is now available

This hotfix will address issues seen between Firefox 4 and the Norton Toolbar in NIS/NAV 18.5 and Norton 360 v5.

You can download the hotfix here: http://us.norton.com/support/kb/web_view.jsp?wv_type=public_web&docurl=20100720113635EN

Currently, this fix is only available by downloading and installing the file on the above site. The fix will be included in the next major product update via LiveUpdate, but it is NOT CURRENTLY available through LiveUpdate.

Also of note: This hotfix will NOT address compatibility issues with Firefox 4 and the Norton Toolbar on the Comcast Norton Security Suite. Tony Weiss Norton Forums Global Community Manager Symantec Corporation