errr..and now i've left it for 2 hours and it's working normally..what the hell is going on?

Is using the arrow keys any faster? I found that works very well.

hmmm...i didnt try that..i'll have a go next time it polays up..still doesnt help with the mouse wheel...its very strange

Try to disable hardware acceleration in Firefox.

• Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

• https://hacks.mozilla.org/2010/09/hardware-acceleration/

Try to increase the value of the general.smoothScroll.mouseWheel.durationMaxMS pref on the about:config page a higher value like 1000 to see if that makes a difference with smooth scrolling enabled.

• http://kb.mozillazine.org/about:config

After doing some tinkering, I think I've found the culprit: a setting on the about:config page called mousewheel.enable_pixel_scrolling. Basically, do this:

1. Open about:config. (Open a new tab, and type about:config in the address bar. When the "Are you sure?" prompt appears, click the button to confirm.)
2. In the "Search" box, type: mousewheel.enable_pixel_scrolling (paste it into the box).
3. The list below the Search box should now show just that one line. Double-click it to set it to False. The setting should take effect immediately.
4. Switch to another tab with a web page longer than one screen, and test out your mouse wheel scrolling. The mouse wheel now should scroll the page normally.

I have no idea why the developers added this setting or turned it on by default, but it was very frustrating - I even considered not using Firefox anymore. That's how integral mouse wheel scrolling is for me.

Hope this has helped you!  :-)

-m

P.s. This solution worked in Firefox version 19.0.2. -m

Edit: Turning the setting back to "True" doesn't change the mouse wheel behavior back. So this might not be the specific setting that's causing the problems - or there might be several. It does appear to be an intermittent issue.  :-/ -m

Have you tried scrolling in other browsers? Is it the same speed?

See also:

• http://wiki.mozilla.org/Gecko:Mouse_Wheel_Scrolling

No reply given here provides a valid solution! The key parameter here is mousewheel.min_line_scroll_amount One should set it to some high value. I've set it to 100 (I use smooth scrolling OFF).

Source: http://askubuntu.com/questions/27270/increasing-scroll-speed

I have tried all the solutions proposed on this thread. All work - at first. But if I close and reopen Firefox, the slow scrolling behavior returns. (And about:config shows that the settings changes I made, are still in effect.

Well, here another one that seems to work: mousewheel.acceleration.start Change from -1 to 1