Because you are now working in a new tab and you have google page and your link in two different tabs. So how the back button will work if you have visited only one page in one tab.

I am not sure I am explaining this well.

When I do a search I have multiple results. I like to open each page from the google search result in a new tab. When I click on any link on the the new tab it will not let me go back to the original page in the new tab.

This did not used to happen in the old Firefox. It also does not happen in IE or Chrome. Only FF4.

I am having the same kind of problem with FF4. For example, I open favorite system craigslist. I looked for an item with search, it display the results. If I navigate to one of the search results, it will go there but when I tried to go back to search results page, the back arrow is greyed out. I originally though the original search results is being displayed in a different tab/windows. But there was no tab/window with the search results. This didn't happened with ff 3.6.

Yes, sounds a very similar problem to mine. It must be a fault in FF4.

If you have Mcafee SiteAdvisor that's your problem. Disable the add-on in FF and your back button will work again; at least it did for me.

Same problem. It's not only with McAfee or Windows, since I'm under Linux (Ubuntu 10.04) and I have the same issue.

Disabling Mcaffee Site adviser worked for me too....Thanks....

i haven't try the solution yet but siteadvisor does work in any OS as it is a FF add-on. Not a executable that only works in only one OS.

I have found a solution here. In my case, I have solved this issue rebooting FF 4 in safe mode, disabling all tweaks I had made on my previous FF instalation. To do this, click on Help->restart with add-ons disabled. When restarting, it will open a dialog box where you can choose what you want disabled.

Hope this will help you all.

yes, it is now working again! Hooray!

I had the same problem. Disabling the MacAfee Site Advisor plug-in fixed it.

But I don't want to disable the McAfee SiteAdvisor! It saved me several times from entering a bad site.

McAfee breaks yet another thing on my computer. Thanks for the heads up on how to fix FF4.

Yes, the problem has been fixed. I wonder if the newest version of SA has this problem licked?

I found out that the problem was corrected by removing an add-on. By trial and error I found that My Web Search Plugin 1.0.1.0 was the cause of this problem and removed this add-on. Go to Firefox and select add-ons and then disable this one or if you do not have this one, disable all of them and then add them back one at a time until the problem reappears.

The problem isn't with FF4 or IE. The problem is caused by McAfee Site Advisor. Open MS Explorer, find McAfee and drill down until you find the folder named SiteAdvisor. Rename that folder to SiteAdvisor.old and your problem will disappear.

Using safe mode, disabling all extensions and add-ins, etc. did not work. But this config change restored normal fwd/back buttons behavior - no clue why it became set to zero ... worked for me anyway - your mileage may vary ...

• in the URL type about:config press enter
• in the search field type history
• find this entry - mine was set to zero ( 0 )

     browser.sessionhistory.max_entries    0

• click on the entry to change it to 999 (or some value > 0)

     browser.sessionhistory.max_entries  999

• the next tab you open will have the fwd/back buttons working

The same problem started in my FF4 right after I installed McAfee SiteAdvisor. Like ckentie, I did not want to disable McAfee SiteAdvisor, but looking through FF4's preferences (by typing 'about:config' in URL bar) I found what might have caused the problem. The following two preferences were 'user set' with the string value 'Secure Search':

        browser.search.defaultenginename
        browser.search.selectedEngine

I recall that right after I installed SiteAdvisor it showed a popup asking me to enable 'Secure Search' (whatever that is!). I had opted not to. Moreover, those two preferences refer to the search box that lists search engines at the top right hand corner of FF4 and it had no search engine in the list by the name 'Secure Search'. There was one called 'SiteAdvisor'.

What I did:

1. I simply change the value of both preferences to 'Google' (which is listed among the search engines).
2. I removed the SiteAdvisor search engine that was installed when I installed McAfee SiteAdvisor, then restarted FF.
3. I reinstalled the SiteAdvisor search engine from the one listed on the FF Add-Ons website (in the Search Tools category). That one did not cause the problem to reappear.

NOTE: McAfee's 'Secure Search' is not to be confused with Google's 'Secure Google Search', which is a search engine that can be added to the FF list.