I just re-installed the FF v 12.0 update, and this problem is gone. Tested all the sites I was having problems with, and no more jumping to middle of page.

In the interim, while I was happily back on v 11, I did several things: updated Java to the new v 1.7.0_04 (FF Java Deployment Toolkit 7.0.40.255/10.4.1.255), updated the Microsoft .NET framework, updated Flash Player to the latest v 11.2.202.235, updated the Silverlight plug-in, and possibly a few other things.

Not sure what caused/cured the problem, but it seems to be gone at the moment. Possibly one or more of the previous versions/updates of my existing add-ons/plug-ins was incompatible with proper browser functioning in FF v 12.

I would advise the small number of FF users having this exact problem to revert to v 11, install ANY and ALL updates to existing software, operating system, FF plug-ins and extensions, and THEN re-install FF v 12.

Sometimes you have to aggressively pursue updates: FF showed that some of my plug-ins were up-to-date, when in fact there WERE new versions available...

I spoke too soon: a scattering of website are still jumping to the middle or bottom of the page when loaded. Fewer than before, but still pretty darn annoying when it happens. Here's one, a product page at NewEgg:

http://www.newegg.com/Product/Product.aspx?Item=N82E16896736134&Tpk=96-736-134&nm_mc=EMC-GD051512&cm_mmc=EMC-GD051512-_-index-_-Item-_-96-736-134

All individual product pages at NewEgg now seem to jump immediately to the bottom upon loading.

And another: http://www.angieslist.com/articles/preventative-screenings-how-improve-your-health-help-your-doctor.htm?cid=ALHD20120516

And another: http://reviews.lcdtvbuyingguide.com/samsung-lcd-tv/samsung-ln32d450.html

And another: http://www.fixya.com/support/t9959952-orange_light_continuously_blinks_nec

And another: http://www.topix.com/forum/autos/toyota-camry/TTPVEUN8TERT6NBKJ/p5

And another! https://www.bankofamerica.com/smallbusiness/

And this one: http://www.classmates.com

And one the original poster cited: http://www.mountainhardwear.com/Men%27s-Running/hxt-mens,default,sc.html

And this very page we're on right now!! (loads in middle) https://support.mozilla.org/en-US/questions/892998#answer-329389

And yet another: http://www.ebay.com/itm/Kindle-Fire-Leather-Case-Stand-Car-Charger-USB-Stylus-Earphone-Purple-/380431232790?_trksid=p3984.m185&_trkparms=algo%3DPI.WATCH%26itu%3DUA%26otn%3D5%26po%3DLCA%26ps%3D63%26clkid%3D8464016013309874939

Tried "Restart with Add-On Disabled" No change.

It may be that certain pages have outdated code that is no longer exceptioned correctly by Firefox 12. But it's odd that the problem pages seem to be fewer in number, and that pages that caused this issue before, now don't...

Hmmm, both of those pages work normally for me in Firefox 12.

If I disable Javascript, they work fine. But that's not a practical solution. Something is fouling up the browser's interpretation of some Javascript functions. Could be any one of dozens of things, but with add-ons and extensions disabled, the issue remains. So perhaps another program or the OS? But the issue does NOT happen in FF v 11.

Very frustrated with Firefox, and can't take the hours/days it would take to run this down. Perhaps if one of Mozilla's main developers encountered this ussue......

Here's a 5-minute exercise: try a new Firefox profile. In addition to bypassing current add-ons and custom settings, it should have completely fresh settings databases and a fresh cache folder.

You can drag the favicon for this thread from the URL bar to your desktop for easy future access.

Close Firefox and start up in the Profile Manager as described in Profile Manager - Create, remove or switch Firefox profiles. On Win7 x64, you can paste this into the search box on the Start menu and press Enter:

"C:\Program Files (x86)\Mozilla Firefox\firefox.exe" -p

Any time you want to switch profiles, close Firefox and return to this dialog.

After getting to the home page in the new profile, before importing any old settings or installing any add-ons, test the links in this thread to see whether those pages work correctly.

Any difference?

None whatsoever. Browser behavior is exactly the same.

Earlier, I had tried emptying cached web content and cached offline web content and user data to see if that would help. There is something in Javascript that my v 12 is parsing incorrectly.

Again, disabling Javascript makes the errant loading cease on ALL problem sites. So it is something in FF handling of Javascript in v 12, as I've said.

It's just freakin' UNUSABLE at this point. It's either scroll back up on half the pages I visit, or deal with the v 11 nag screens that pop up 4-5 times a day....

To paraphrase the guy in "Jaws": "I think I'm gonna need a better browser."

still the same here also. i am now using waterfox and pale moon v 12 with success. those are the 64 bit versions of firefox. java script works .

Love to try it, but have Win XP 32 bit on both computers. Looking at Chrome....

I love Firefox and have several very useful developer extensions (I build websites among other things), but unless this issue is fixed by v 13, they've lost me.

Interesting- just noticed that all/most of the pages that jump, go to user input boxes, or places where user input might be required. (Except for the NewEgg, which I haven't figured out get, perhaps account sign-in link...)

So Firefox 12 is automagically loading those pages to a spot where Javascript code creates a user input/action space. Obviously, a mis-interpretation of Javascript on my systems, which is only being experienced by a handful of other FF 12 users. Wish I could figure out what's causing it, but 3 hours work yesterday yielded absolutely no results.

Interesting- just noticed that all/most of the pages that jump, go to user input boxes, or places where user input might be required.

Does the cursor move into the box, i.e., if you start typing, text appears in that box? Some pages do this by design, such as the Google home page moving the cursor to the search box, but if you see it happening on every page, then something else is going on.

chrome is very quick. try majorgeeks browser section also. there are a couple there that are better than what mozilla USED to offer. try the slim one

No, the focus does not shift to an input box, just the location of it on the page. And it's not always an input box, sometimes just the middle or bottom of the page. And it always seems to be exact middle, or flush bottom. Looked at some source code, and it would be very difficult to tease out which function is malfunctioning.

Since you have demonstrated that the problem occurs on your system in a new profile with zero customization and zero add-ons (other than globally installed plugins), I wonder whether Fx12 has a new incompatibility with something external to Firefox, such as your mouse/touchpad driver, or screen recording/screen reading software? Even malware could be a possibility.

As a short term workaround, you could use a Greasemonkey userscript to reposition pages after load. One negative side effect is when you reload a page you're viewing. Normally, Firefox restores your earlier scroll position, but this script undoes that. Perhaps there is a more sophisticated solution that would resolve that.

// ==UserScript==
// @name        To Top of Page
// @namespace   YourNameHere
// @description Reposition page at the top
// @include     http*://*
// ==/UserScript==
function rePosition(e){
  if (!window.location.hash) window.scrollTo(0,0);
}
window.setTimeout(rePosition,250);

Malware not likely, as others do have this problem. Thorough scans w/ McAfee, Defender, and Malwarebytes reveal nothing.

Could be a new/updated program or driver. Things I have updated in past couple weeks or so include: new Java 7, Microsoft .NET platform, Silverlight, and my onboard card-reader driver. I don't think I want to change or tweak anything, as the rest of my system is running fine. With the increasing number of websites affected (including banking sites!), I think reversion to v 11 is my best bet. And, of course, trying Chrome and some other browsers to replace Firefox entirely.

Oh yeah, I do have both a wireless Logitech mouse and a Wacom tablet in use, but they have never caused any issues before.

This won't help anyone here, but just so you know -- I use Chrome and it has been doing this as well. It happens to be the GoDaddy site and they're trying to figure it out as well, but we're all stumped. (only if I'm logged in ... when I'm NOT logged in, it doesn't happen).

I just didn't want you to think it was an exclusively FF problem!

Thanks Bbigham. Good to know. However, I get NO errors on any of the problem pages in either IE 8, or FF 11. So the problem, from my perspective, appears to be exclusively with Firefox version 12. My guess is that this has something to do with HTML5 and/or latest CSS, and some websites having code that just doesn't work right on computers with certain programs (.NET framework?). If so, it's negligent that new codes are not made retroactively compatible in FF 12. My guess is that Chrome is creating the same problems for some people.

I'm seeing this issue on various sites whether I am logged in or not. Did not see it on GoDaddy, but I was not logged in.

Just installed Chrome. It's kind of a clunky browser, and seems to take 2-3x as long to fully load some pages, but it has absolutely no cache or history or passwords, etc. So it will probably speed up as I use it. But the amazing thing is: NO MIS-LOADING ON ANY OF THE PROBLEM PAGES I've been compiling on one of my previous posts.

So this issue is clearly on Mozilla's end, in my mind, even though only a few people have it.

"Change is good," but in Firefox's case, it will drive some people away.

many different browsers out there. majorgeeks has most of them. chrome and slim were the fastest for me. opera has many excellent features. ie 9 much better than previous versions. right now im still sticking with waterfox and pale moon , my firefox v 12 just doesnt work for me

Good points chuddds, but I'm stuck on 32 bit XP at the moment, so choices somewhat limited. Once I get a new machine w/ Win 7 or 8, I may try some of t'others. Chrome is a little bare (after years of embellished Firefox), but I'm kind of liking it.

I think Firefox kind of went downhill when they went into the rapid development cycle. Too many incompatibilities, issues, etc. (I'm on the 9th consecutive version that does not recognize that I HAVE the QuickTime plug-in, fer crissakes!) It was really quite good for awhile there.

almost of these browsers work in x86 XP

http://majorgeeks.com/download.php?id=5&sort=25