Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the add-ons is causing the 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

I have the same problem using Firefox version 3.6.16 on Windows 7.

Steps to reproduce:

1. open a new empty Tab in Firefox
2. enter a website URL on that Tab (e.g. "www.google.com")
3. click on a link on that website (e.g. "Advertising Programs")

The history back button is supposed to be enabled now so you can navigate back to the previous page, but it isn't! It is still disabled.

This might be a problem with the McAfee SiteAdvisor plugin. When I deactivate this plugin the issue does not occur anymore. My version of the McAfee SiteAdvisor plugin is 3.3.1

Can anyone confirm this?

I believe schnabel is right. I disabled the McAfee SiteAdvisor plugin and the issue was solved for me.

For those of you wondering how to disable this feature:

1. Click "Tools" in the top bar
2. Select "Add-ons" in the drop down menu
3. Choose the "Extensions" tab
4. Click on the McAfee SiteAdvisor to bring up the Disable button, then select disable

I was having this problem and didn't want to disable the SiteAdvisor. I went to the McAfee SiteAdvisor download page and reinstalled. I don't have the problem anymore. I can navigate to the original search list again. I am working with a Vista PC. My friend tested the issue on his Mac, and he doesn't have any navigation issues, even without a new install, but his might be updating automatically. Hope this helps!