FF used to work flawlessly. Since installing 4.0 I am blocked from some secure sites with log ons hanging or even just watching a YouTube video. Please get this fixed quickly. I hate having to use IE but at least it works!

I HATE this new version of Firefox. I've lost my ability to print articles from Google sites + my Bookmarks have vanished. How do I erase this Thing & restore the previous, wonderfully intuitive version? or do I just dump Firefox and go back to IE?

I reverted to the older version of Firefox and it still works perfectly. 4 version froze up on me constantly and I had to shut down all the time. Now it is great again. I just wish it would quit asking me to update to 4.0 'cause I WON'T! I hope they fix it soon.

I just went to my downloads and installed the older version.

Disable all addons:

Help => Restart with addons disabled => Click the button "Continue in safe mode". If it works you have an addon that is conflicting. Enable one at a time to see which one then disable it.

I downloaded the older version but find it still hangs but slightly less. Probably time to uninstall the whole thing and use chrome.

Yep, I'm with you. I just became an official member of the Firefox site with the sole intention of letting you all know how awful Firefox 4.0 is. It stinks! It runs slower than the older versions, and I frequently have to 'force quit'. My tab-tree app doesn't work well with it (though this is a glitch that is up to that app's designer to solve). All in all, after 5 years of happily running Firefox, I am seriously considering going to Chrome. I'll probably give it a couple more days before I actually pull the trigger, as I really want Firefox 4 to work.

In other words: FIX THIS VERSION, YOU'RE LOSING FAITHFUL FIREFOXERS!

It doesn't seem to be something Firefox can fix. Norton for example openly says it's toolbar and IPS is not compatible with firefox 4.1 and are currently working on a fix as of the 29th. Lets not get too hasty and blame the developers for it. It seems to be working fine on some computers, probably because they aren't running Norton or whatever other program it is that's causing the program to freeze and crash. Norton says expect the fix within a week. I don't know what the other companies are claiming. I use Norton so I did the research for it. Bug them, not Mozilla(:

But I don't use Norton...

I just tried FF4 again and am now back with 3.6.15. I can't believe they thought they could just do things like get rid of the status bar and no-one would notice or care? I went to one Mozilla web-site and my toolbars turned dark blue with the text unreadable because is was still in black. How stupid!!!

Now that I've reinstalled the older version, it keeps locking on me and I have to use the task manager to kill the process. I really hope I don't have to reinstall everything from scratch just to get back to where I was! What a mess!!!!!

Firefox developers - listen to the feedback and give us what WE want, not whatever fancy features you personally like. I want a working browser!

First i noticed system wide extremely poor performance, when i looked firefox 4.0.1 uses 300% of the ram which its predicesser used. Then i noticed that while idle firefox continues to increase its ram consumption. I only have 2gb of ram for everything. it takes nearly 1/4 of that simply for microslug to boot. I am using opera for some purposes and its current version is using about 20% of what the previous version of firefox consumes. Something is really wrong with version 4. in my case its causing my system to swap.most of the systems i see have less ram and slower processors than this one(not by any means my fastest or largest system.

Cutting your footprint back to something like 50mb for a single window 5 or 6 tab would probably solve all of my problems.

Name a browser that will only use 50MB for a single window with 5 or 6 tabs open. Chrome is the only one that I know, but it runs each tab in a separate process and overall takes a lot more than a total of 50 MB combined for 5 or 6 tabs.

If you are setting a "spec" of 50 MB, you need more RAM or a newer PC - or to stick with older software versions.

It's now 2011, not 2001! - when PC's came with 64MB or 128MB of RAM.

as mentioned above Opera 11 uses about 30mb. the-edmeister seems to miss the point that a 2gb machine should work well with things. stepping back on firefox has restored performance you are right that my 4 year old machine came with 2gb of ram as compared to the 256mb which was common in 2001. however a program which hogs 800 mb of ram all to itself and simply leaks another 500mb has problems which must be fixed.

too bad you missed that this machine is reasonably new (last of the xp machines). guess you should look into Opera. One added feature: Opera and Firefox play nice with each other both being open at the same time. its helpful with yahoo to have both open

I have used Firefox since it first came out, and always loved it. Firefox 4.0.1 is a different story. This must be one of the worst software upgrades across the board, of any software package I have ever used. I have stuck with it for a few weeks, and I have now finally given up.

Constant crashes, constant freezes, many plugins no longer work, my favorite among them, i.e PDF plugin to see PDF files inside the browser. AppTabs disappear over and over.

I have downgraded back to 3.6.17 and hope things will be better again.

I downloaded FF 3.6, but when I tried to install it I was told that the exe file is not a valid Win32 application. Go the same message when trying to update Adobe Flash Player. What gives with that? Firefox has been great until I made the mistake of "upgrading" to 4.0.

I gotta tell ya' folks...this new Firefox (as those darned kids say - I'm 59) really sucks. I run a computer repair business and I design, and, host web sites for a living. I'm at a PC day and night. I've been screwing with thing for the last few months, on dozens of computers, and it's utterly horrible. On my wireless laptop - out in my living room - it won't even connect to a lot of sites. It opens slowly, hangs up, and is just generally broken. I have almost no add-ons/plugins enabled, either. I just clicked a link to install Firebug and - as is often the case - it hung up and had to be closed. I don't know anything about programming but this thing is fundamentally flawed. I've started using Chrome and Opera - even Internet Explorer, with all of it's security vulnerabilities. Fix this or it will become footnote to open-source history. How can the developers be unaware of how poorly this design performs...? And how can the "team", in good conscience, recommend that folks upgrade? This constitutes a bad beta release. I just downloaded version 3.6.x (something or other) and it works, now.

Wow - what a freaking nightmare.

I have a built-in biometric reader on my laptop and since downloading FF4 I cannot use the danged thing. I actually reverted to the previous version in order to be able to use it. However, I did have a need for FF4 due to some of the features it does offer which interact with an online application that I use frequently. But that doesn't mean I like it. I actually have both versions running on the same desktop.

But not I'm being prompted when using the FF4 browser to download and update to FF5. I'm afraid to expecting that it will wipe out my older version in the process. What to do?

After much annoying 'download the latest version' I downloaded Firefox 4.

My first impression was 'so how on earth do I use this?' No menu..now that's really intuitive.

My hubby gave up as he was totally confused. He uses a sub account and BT Yahoo looks completely different with missing icons and links. Note that my main account looks fine, but sub accounts get something that looks like a fraudulent website even though it isn't.

I have managed to return the various menus and relocate all the icons that were moved to illogical positions. eg 'Home' icon stuck on the far right of a navigation toolbar.

Still not had any response regarding the weirdness of why my computer with a main account and a sub account with only one version of Firefox 4.0.1 manages to view the login page of Yahoo completely differently.

Please forward feedback via 'About' 'Contact us' scroll down the page and on the left you will see Feedback link.

I am finding that Firefox 4 and now FF 5 work fine. I was able to rearrange the toolbar buttons back to where I want them, I found out how to redo other tweaks that I had before, and I like the new bookmarks menu in the bookmarks toolbar. Since I use a Mac, the menu bar cannot be disabled, so no problem with that. I did have to get some new themes, since some of my favourites were not updated for FF4.

I read the Mozilla development newsgroups, and for a while there was a discussion about FF4 not providing any information about connections when a page is loading. The developers were thinking it really was not needed, and maybe they could just use idiot lights to tell what sort of process was happening without giving details. They got so many negative responses to that idea that they decided to provide the information in the same box where you get the link destination info.

With Windows, if you want the menu bar or any other bar back, you can get that by right-clicking the navigation toolbar and checking whatever bars you want to see, can you not?