These keyboard combinations should still work. Sometimes there can be problem with plugins and they keyboard. Is your problem happening on a specific page? Does it help if you click on the page outside any flash or other plugins first?

I tried it with a new profile and it still doesn't work on any website. What does happen is, that I go back/forth in history when I press page up/down.

Does it work for you?

You may have switched on caret browsing.

You can press press F7 (on Mac: fn + F7) to toggle caret browsing on/off.

See http://kb.mozillazine.org/Scrolling_with_arrow_keys_no_longer_works

• Tools > Options > Advanced : General: Accessibility: [ ] "Always use the cursor keys to navigate within pages"

I have no idea, what caused the problem, but it suddenly disappeared. I know this doesn't make much sense ("Have you tried turning it off and on again?" ^^). If this bug occurs again, I will post it in this thread.

Edit: It happened again... updating the first post.

I had this problem. I solved it by unpinning the tabs I had pin. It is a cool feature but worthless if I lose my scroll keys and home and end keys. Unpinning the tabs immediately gave me my scroll functions back.

I didn't use the pin function.

All I have to do is:

1. create a new clean profile (optional)
2. activate the flash plugin (if not already activated)
3. visit the youtube.com front page (no login or anything)

When I do that, the bug doesn't go away any more until I close the browser. Maybe this is just a flash problem, but it's a bit ridiculous that it affects the whole browser. Killing the plugin-container.exe doesn't help.

I tried another site: When I go to kongregate.com i can still use page up/down normally for a few seconds, then the behavior suddenly switches to going back/forth in history.

I also face this problem: Page Up/Down doesn't scroll page, but Go Back/Forward. I turned off the Caret Browsing already, but this doesn't help. Is this a FF4's bug? But it's OK just 1 day ago. Go crazy!!!

I found a way to fix. Open IE, and use Page Up/Down button, it's OK. When I go back to FF4, they also work again. I don't know why, but they're fixed. Strangely!!!

@bestest_boy This doesn't work for me. Do you just switch to IE and then back to Firefox, or do you have to shut it down?

Btw: Do you still have the problem, when you turn of all plugins? I figured out, that the problem occurs, when any plugin (java/divx/flash) is used.

I have the same problem after updating to firefox 4 even if the site has flash or not

@cirno: I only need to open IE beside FF4, no need to restart FF4. I also didn't disable any plugin, addon. I don't know what is the really reason but it works for me. Now it's OK.

It has also been reported here: http://support.mozilla.com/en-US/questions/795539 http://support.mozilla.com/my/questions/799752

And on bugzilla here: https://bugzilla.mozilla.org/show_bug.cgi?id=640587

There are two ways to fix this problem. Each of them worked for me.

• Option a) Enable a hack, described here https://bugzilla.mozilla.org/show_bug.cgi?id=640587#c48

OR (cleaner)

• Option b) Update your Touchpad-Drivers. For me (Asus UL-80VT) this driver worked (ElanTech Touchpad Driver v8.0.7.0 or later) http://www.techspot.com/drivers/driver/file/information/14513/ v8.0.5.0 and earlier did NOT work.

Don't ask me, why a Touchpad driver messes up the keyboard configurations. v8.0.5.0 was even whql certified...