Sounds like it's a programming error in FF4, something I'm very surprised wasn't noticed by any of the "millions" of testers. This tells me that either:

1. The coding affecting the back/forward buttons changed between beta and RC, and/or RC and official public release (unless the RC was unchanged). Thus, the errors were not existent in the beta testing, and thus nothing was reported--no problem, nothing to fix.

2. It was noticed by some, but a small enough number that the problem was disregarded by the programmers/developers as an anomaly.

3. It was noticed by many, but the testers didn't consider it significant enough to report. - Unlikely

4. It was noticed by many testers and reported, but the developers chose to ignore it anyway. - Unlikely

5. It was not noticed by anyone despite the problem existing. - Unlikely

The first two options are the only likely explanations I can think of at this time. But it's my hope that it's fixed in a soon-upcoming update.

yeah...me a firefox user since 1.0, this is the first time i m a bit annoyed and not satisfied with firefox's latest and newest release.

dont get me wrong. such a basic feature yet very important feature for everyone to use, from beginnner to advance. Imagine started to download and use and get this problem....

time to consider moving to chrome.

It works for me now because I deactivated McAfee SiteAdvisor add-on! :-) Thanks so much.

This (starting in safe mode) at least makes it work - I started it that way and then with all plugins disabled. In both cases the back button worked. I added by add-ons back one at a time and it turned out to be Yahoo! Toolbar that was the one screwing up the back button in my case.

Yes! This was a solution for my case! Removing Yahoo Toolbar solved all the problem. Thank you!!!

Yep, that was the problem for me too. Was working fine yesterday and then this morning the problem showed up out of the blue, but removing yahoo toolbar sorted it. Thanks for the tip.

I have also this Back Button problem and where I noticed it first was on Web sites using frames. After connecting to such a frame base site the Back Button remained grayed out irregardless of how many levels I was browsing. The only way to get back was to refresh the main, top Web address and start from there again every time. Not a very pleasing way of browning for reading news etc. In the end I found that it was an add-on the was the culprit. After disabling the Ancestry.com Advanced Image Viewer, version 1.0.0.1 the Back Button started to work again. I have had this viewer installed in all my previous versions of Firefox for several years now without any problems. I therefore have a strong feeling that the present implementation of the Firefox 4 Back Button is extremely fragile to say the least. I think the software developers should consider this a serious weakness in this version.

this isn't a fix but if you right click your mouse when your at the back button it will give the history and go from there like i said it's not a fix but it works on mine

Use one of these methods to open the tab history list:

• Right click on the Back or Forward button
• Hold down the left mouse button on the enabled Back or Forward button until the list opens

You can look at this extension:

• Backward Forward History Dropdown: https://addons.mozilla.org/firefox/addon/backforedrop/

I have some issue. I do find a workaround. When I see the button disabled, I click on another tab and then go back to the initial tab. The button will enabled. This doesn't solve the problem, but just allow me skip the frustration and keep doing what I need to do.

Using safe mode, disabling all addins and extensions did not help. But this did work in my case: type about:config in the URL area and press enter type history in the search area and press enter find this entry (mine was set to zero)

  browser.sessionhistory.max_entries    0

click on it and change it to something > 0

 browser.sessionhistory.max_entries  999

the next tab I opened had fwd/back buttons enabled again

No McAfee but YES I have the same problem.

This did not work for me. Are there any other about:config fixes you might recommend?

YES! That was it. Thank you so much. about:config change browser.sessionhistory.max_entries 0 to browser.sessionhistory.max_entries 999 I was so frustrated!

I abandoned the increasingly disfunctional FF4 (pity - I was a Beta user...) and reinstalled FF3.6 only to get some dumb error message: "The bookmarks and history system will not be functional because one of Firefox's files is in use by another application. Some security software can cause this problem".

I'll put up with some hassle, because I liked FF in the past, but enough is enough. Back to IE for me. Bye... (for now)

I am experiencing this issue as well on Mac OS 10.6.6. Have disabled all plugins and add-ons. No other resolution but to downgrade to FF 3.6.

I'm also having this problem on Mac OS. Bit of a pain in the @rs3 so I'll be onto Chrome until it's fixed.

I had the same problem after installing Firefox 4 - solved it by enabling Navigation Toolbar. Go to View>Toolbars> then enable Navigation toolbar. The back/forward arrows and the address bar then appear.

I found that going back to FF Vers 4 didn't solve the problem. Where the back button was working BEFORE the 'Upgrade' it was NOT working after I re-installed Version 4. WTF..!! What to do NOW? I cannot go back by ANY means whatever as Command (back arrow) doesn't work anymore either!!

I'm having this problem in FF 5. It's amazingly annoying.