Google plus says "Your Browser is no longer supported" for firefox, clearing Google cookies may help!

It appears that Google+ requires newer version of the latest Firefox 5.0. Google+ does't seem to work properly on Firefox 5.0 because Google sets cookies time to time and whenever there is a conflict like an unsupported browser, Google sets a new cookie for it and if that is not cleared in time you are going to get the "Your Browser is no longer supported" message.

For clearing cookies do the following:

• Go to the Firefox options
• Click on Privacy tab
• Click on remove individual cookies link
• Look (search) for google.com as well as .google.com cookies and remove all of them
• Restart the Firefox 

If clearing cookies doesn't help, try changing user-agent. Follow below steps:

• Go to the url https://addons.mozilla.org/en-us/firefox/addon/user-agent-switcher/ and install the Firefox plug-in
• Restart the Firefox.
• Switch user-agent to IE8. 

If you don't see the safari icon on the navigation bar, then right click somewhere on the navigation bar, click on the Customize... link, find the safari icon and drag it to navigation bar.

It should work.
Note that this issue is not related to Google+ but with Google Profiles, more about this can be found here: http://www.mail-archive.com/support-seamonkey@lists.mozilla.org/msg23737.html