Recently when I updated Firefox on my old machine from 3.2 beta to 3.5 beta I lost the forward and back buttons on the navigation bar.
It just needed a few tweaks in the settings to fix it,just right click on the navigation bar and click on customize and drag the forward back buttons from the customize toolbar window onto the navigation bar, and you are done.(Marked with the red arrow, see the accompanying images )
Update: Found out from a friend that in some cases the Home button is also missing, you can use the above method to restore that too, find the home button on the Customize Toolbar window and drag it to where you want it.
If you haven't already got this, you can get the latest version of Firefox from here
Need a solution for any other issues with Firefox 3.5 beta? let me know about it in the comments.
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