• "Clear the Cache": Firefox > Preferences > Advanced > Network > Offline Storage (Cache): "Clear Now"
• "Remove the Cookies" from sites that cause problems: Firefox > Preferences > Privacy > Cookies: "Show Cookies"

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of your add-ons is causing your problem (switch to the DEFAULT theme: Tools > Add-ons > Themes).

• Don't make any changes on the Safe mode start window.

See Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems and Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems

Thanks very much. I did all that. I cleared the cache. I removed cookies. I disabled all add-ons. No change. So I uninstalled and re-installed Google toolbar. Still no buttons - just the grey space where the bar should be. And still no buttons appear in the box when I go into Firefox>preferences>manage add-ons>preferences>buttons. I'm an amateur at this so I'd welcome other thoughts

I have the exact same problem with Firefox 3.6.12 in Windows XP.

My wife has Windows 7, and this problem did not occur for her.

I will follow with interest your dilemma and the suggested solutions (if any).

You can try "Reset all user preferences to Firefox defaults" on the Safe mode start window.

Create a new profile as a test to check if your current profile is causing the problems.
See Basic Troubleshooting: Make a new profile

There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins"

If that new profile works then you can transfer some files from the old profile to that new profile (be careful not to copy corrupted files)
See http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Thanks, cor-el! :-D Making a new profile, copying over only the bare necessities from the old profile to the new and deleting the old profile worked! Only took about 20mins, which is nothing compared to the amount of time I have spent the past few days troubleshooting and searching forums all over the inter-webs. Thank you, thank you! Woohoo! :-D

Cor-el Thanks again. But when I tried to open the Profile Manager through the Terminal box - there's nothing. It says there's no such file. So I couldn't even get to the first step!

I tried again and got there. But when I created a new profile all my default profile was copied across into it. And that opened a second background copy of Firefox. Which meant I couldn't open Firefox at all. Which meant I had to delete the new profile. I think I must be very hamfisted at this. Is there an easy way? Or is it best just to give up.....

I tried making a new profile, but when I installed Google toolbar on the clean profile, the toolbar did not show up and was not on the list of available toolbars. It seemed like a good idea, but not for me. (Windows XP)

Hi just solved the issue by deactivating all add-ons named "java console" (all of them whatever the version number). Google toolbar is now OK for me

:o)

Apparently Java Console is no longer supported (it doesn't work with Sun Java) so uninstall it and your Google Toolbar buttons should come back. In researching this I also found out that one should probably disable (or uninstall) the Java Quick Starter. Apparently it makes you vulnerable to a worm that will cause the Firefox browser to be redirected to sites that you didn't request.