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). 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

If it does work in Safe-mode then disable all your extensions and then try to find which is causing it by enabling one at a time until the problem reappears. You can use "Disable all add-ons" on the Safe mode start window to disable all extensions. You have to close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")

I also noticed the Feedback button was missing. I tried starting in safe mode, using the default theme, but the Feedback button was still gone. Any other ideas?

i cant find feedback button again

the problem to inform: freeze plugin container

I've lost my feedback button as well, and opening in safe mode didn't help nor did disabling all the extensions.

FF 4.0 beta 2 Windows Vista Home Premium SP1

Plugins

Adobe Acrobat 8.1.3.1.87 BS Contact VRML/X3D 7.205 7.2.0.5 BS Version 1.0.0.6 DivX Player Netscape Plugin 6.1.0.0 DivX Web Player 1.4.3.4 Java Deployment Toolkit 6.0.200.2 Java Platform SE 6 U20 6.0.200.2 Microsoft Office Live Plug-in for Firefox 2.0.2313.0 Quicktime Plug-in 7.6 Shockwave Flash 10.1.53.64 Windows Presentation Foundation 3.5.30729.1

I somehow lost the feedback button earlier as well (not sure what the cause was, I figured it was a bug that occurred because I installed a nightly build then went back to 4.0b2, but perhaps not).

Just to make sure the Feedback/Test Pilot extension (which is what shows the Feedback button in the betas) isn't disabled, go to Tools -> Add-ons. If it isn't, go to https://testpilot.mozillalabs.com/ and click Download Test Pilot. After that gets installed and you re-launch Firefox, you should get your Feedback button back!

Thanks Chris, tried that, didn't work had to re-install.

I think it disappeared originally when I changed my privacy settings and cleared my cookies it seemed to cause other UI problems as well so we'll see how it goes from now on.

No feedback button, but I do think this is intentional by Mozilla. As far as the squewed back button, I looked at very, very close and do not find it not circular.

No feedback button here either. might be useful to add an access to Feedback & bug reports through a menu?

It happend to me twice in two machines, I thougt that it has happend when I start the firefox 3 with the same profile, then return with firefox 4...

I solved it dissabling and enabling "feedback 1.0" extension.

Eloyesp's solution works to fix the missing Feedback button and menu.

Sadly, submissions through either menu or button results in 403 Forbidden errors again.

i had the same problem, but i solved it by disabling and re-enabling the feedback add on.

I had the same problem with a different twist: Chatzilla was installed on Beta 1, and there's not an update for Chatzilla on Beta 2 yet to it's disabled now. However, I added a button next to the Feedback button to launch Chatzilla, and when I started Firefox the Chatzilla button was there (and it even launched Chatzilla, despite Firefox telling me that Chatzilla was disabled) but the Feedback button was gone.

Upon disabling the Feedback add-on, the Chatzilla button disappeared. After re-enabling the Feedback add-on, the Feedback button returned but the Chatzilla button is still missing.

My feedback button is also missing. Happened sometime today, not sure why. I ran B2 for a few days with the feedback button still there.

I was having this problem as well, but it sounded like someone's comment about add-on compatibility might be relevant. I disabled the two add-ons I thought would be most likely to be incompatible, and that I use the least (sync and "copy to word perfect lightning") and now my feedback button is back! Since sync is a common add-on, maybe that's the one that's causing people so many problems.

Ahhh! I spoke too soon! While the feedback button is back, when I tried to use it I got the following message: "Oh! So, you want to offer us feedback on the next version of Firefox. Thank you, but you'll need to be on our latest beta. To do that, simply go to our download page and install/update to the latest Firefox Beta!(link)" I clicked on the link, hoping there was just a new version out, but no, it's the same one I already have. Downloading it again did not solve the problem.

As for the elongated back button: do you have any third-party (addon) buttons located in the address-bar bar?

I use TagSieve, and if I place the command-menu button next to the address-bar, I find that the back button is stretched too. Remove it, and it goes back to being a circle.

I suspect this is a compatibility problem with your add-on. Maybe you can report it with your Add-on Compatibility Reporter?

I just removed the Test Pilot addon. My Feedback button returned!

It seems that in the Beta versions, it's not Test Pilot, but the "Feedback" addon which gives you the option to send feedback!