Google Toolbar extension login problem starting around 09-17-2011.
Google changed the login address for their "accounts" and you need to edit the address to the new one.

• Open your Profile folder.
  https://support.mozilla.com/en-US/kb/Profiles#w_how-do-i-find-my-profile

• With Firefox closed, open the \extensions\ folder in your Profile folder, then locate this folder and open it.
  {3112ca9c-de6d-4884-a869-9855de68056c}

• Then you need to open the \lib\ folder to see the toolbar.js file. Open that file in a simple text editor program.

• Edit every occurrence of www.google.com/accounts to accounts.google.com - using the Find feature in the text editor - (I counted 15 times that address appeared in the toolbar.js file) .

• Save the edited file. Then start Firefox.

Thank you. I findGoogle sloppy with their users sometimes...

I couldn't find the toolbar.js file. Any other ideas?

Attached is a small screenshot of my folders.

Thanks. Worked like a charm. Only thing I had to restart computer after the change. One thing that baffles me is when I click on either www.google.com/accounts or accounts.google.com it takes me to same page!

I still cannot find that folder that you spoke of, nor can I find the toolbar.js file

This is getting annoying, since it seems all you can do is spit out the same response on 100 threads, but never go back to look for the ones that it didn't help...

@Arcturus72

Sorry I don't have the time to keep track of all the threads that I post answers in here. You could have sent me a Personal Message requesting more help and with a link to this thread.

You have the wrong extension folder open - for an extension named flashbug - not the {3112ca9c-de6d-4884-a869-9855de68056c} folder which is the Google Toolbar.