Review your computer's Accessibility settings.

Ensure that your computer's keyboard is setup as a standard QWERTY key layout.

Did you try to close and restart Firefox or reboot the computer?

You can view an identical thread here.

i have done all of the above, uninstalled ans reinstalled more than once this week alone, it works for about an hour then happens again - hence why i am not using proper capitals in my sentence...it is a mozilla problem - my laptop is set up correctly and have had it look at it to be sure- i do not have this issue with ie

If the issue continues to occur again after usage, there must be a file on your computer causing the key configuration to change.

Try scanning your computer for the following:

• Viruses
• Malware
• Bad Registries

Please report back soon.

I had this same problem, and it came at the end of a bunch of problems I started to have with my computer. It started with my bank site. I would hit the drop down arrow to choose which account to transfer funds, and the screen would not stay on to see my accounts. I called the bank and called the bank internet techs and no one had ever heard of that problem before so I knew it was my computer. Over a few days, I started having other problems such as any screen that had a tab for scrolling it would just start scrolling on it's on and you couldn't stop it. It would just scroll to the end of the bar and stop. Then when I tried to print most anything, the box that shows which printer that I was using would only display Microsoft xps writer and no matter how many times I'd click on HP printer it would just click back to Microsoft xps writer. And weird other problems too. Everything else seemed fine, and my keyboard and mouse seemed to be fine. I tried multiple computer restarts and scan checks, reloaded Firefox, tried every known troubleshooter problem with everything and everything said it was working normally. Tried unplugging keyboard and mouse, no luck. So I finally thought it had to be the keyboard and bought a new keyboard, Nope - same problems. Okay last resort, bought new mouse. That was it! ALL my problems went away with the new mouse. Nothing to do with file corruptions, viruses, software with related stuff. Just that %U#$ mouse. Hope this helps someone out there.

Was the shift key working while using Internet Explorer? I'm trying to help my in-laws who are having the same issue with Firefox, but not IE.

I was using Firefox, not IE. Yes, all keys seemed to work just fine, as well as the keyboard and mouse, which made it so weird and hard to figure out. But it was all the mouse. I guess it had cancer.

Thank you, it was indeed the mouse for them as well. Weird.

I'm glad to have found this thread because for ages I've not found any answer to this (or something similar), which has plagued me for years. I wonder if we can make this reproducible.

I have the problem when using some Flash pages, using Chrome not FF, on both a Mac and a PC. So I'm purty darn sure it's something about the page.

Here's a puzzle page on the NYTimes site. http://www.nytimes.com/ref/crosswords/kenken.html Doing the puzzle requires holding shift down at times. Rarely, while I was holding it down (of course causing auto repeats to fire), the browser would Back, causing my puzzle to be lost.

I've traced it down: two separate taps of Shift will (almost always, gr) cause the brower to Back. Soooooo, since this is a Flash game, I'm wondering if there's something about Flash, or something about how this puzzle/game is coded in Flash.

One hypothesis is that two taps cause Back, and when I hold it down causing auto repeat, if that hiccups the stream might get broken up so it seems like two taps.

The games doesn't seem to have a discusssion forum so I can't ask the users.

You can try to set the mousewheel.with_shift.action pref to 1 on the about:config page (default = 2; go back in tab history).

• You can open the about:config page via the location bar
• http://kb.mozillazine.org/about:config

See Preferences for customizing delta values and default action:

• https://wiki.mozilla.org/Gecko:Mouse_Wheel_Scrolling
• resource:///defaults/preferences/firefox.js

0 means "Do nothing"
1 means "Scroll contents"
2 means "Go back or forward in the history"
3 means "Zoom in or out the contents"

Cor-el, that sounds highly likely - just wish I was having the problem with FF - I'll try to find out how to do the same with Chrome. Thanks.