Have you tried using a different mouse?

Yes, I tried with another mouse, and with the touchpad, and the arrow keys - it still gets choppy and the only way to fix it is to use the autoscroll for a second... until it gets choppy again.

Please provide your System Details.

Keep task manager open. Do you see anything unusual in task manager when scrolling becomes choppy?

i7 3610QM 8GB DDR3 128GB SSD Intel HD4000 + NVIDIA GT650 2GB (but I guess FF uses the integrated graphics only, tried to force it to use the NVIDIA but the option is unavailable (also I don't think that should be a problem since I'm not using hardware acceleration)).

When the scrolling is normal (smooth) the firefox.exe process takes up to 6-7% of the CPU activity when scrolling. When it's choppy, it's max 3% (according to the Task Manager)

I am using Firefox 26.0 in Windows 7 Professional 32 bit and I am not experiencing any scrolling issue.

If you are on a 64 bit machine you may face issues like this.

Yes, it's 26.0 on Windows 7 Ultimate 64-bit. So it's some sort of incompatibility issue?

Yes.See the screenshot.

This only means that there is only one 32 bit Firefox version that can be used in a 32 bit and in a 64 bit Windows version. Firefox should run fine in a 64 bit Windows version.

Probably i found solution. I dont recall when this was implemented (changed?), but not so long ago if i'm correct. browser.sessionstore.resume_from_crash -> set it to: false.

On: i5 2500k, 570 gtx, 4gb ddr3, ssd 128gb ocz and hdd.

http://oi61.tinypic.com/5akeg7.jpg After scrolling about 30 sec or 1 minute, faulty one (chopping) on the right (left side - normal situation). Picture is before when i discovered solution, when was set to true.

http://oi62.tinypic.com/1193peb.jpg True

For me scrolling was choppy after visiting some websites (after some time). It is difficult to reproduce this problem, it may look like it is random. It is hard to explain..

Screenshots taken at addons tab, where scrolling was unacceptable.

edit: well, problem still occurs..

You can check for problems with the sessionstore.js and sessionstore.bak files in the Firefox profile folder that store session data.

Rename (or delete) the sessionstore.js file and possible sessionstore-##.js files with a number and sessionstore.bak in the Firefox profile folder.

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox
• http://kb.mozillazine.org/Multiple_profile_files_created

Deleting sessionstore.js will cause App Tabs and Tab Groups and open and closed (undo) tabs to get lost and you will have to recreate them (make a note or bookmark them if possible).

You can also try to increase the value of the browser.sessionstore.interval pref on the about:config page.

• http://kb.mozillazine.org/browser.sessionstore.interval

Before that was written i deleted all files in Firefox profil: sess*. Dont work.

Also i was using browser.sessionstore.interval to 600000 and browser.sessionstore.max_tabs_undo to 5. Dont work.

I was going to post another screenshoot, but things went normal in the same session with firefox (it was about 10 minutes or more), it affected core nr 4.

I tried many things. Clear profile with must-addons, disabling/deleting addons. Drivers up to date. Aurora/nighlty. Using bios defaults..