I fixed the problem in Firefox. The scrolling feature does not lag at all now.
I did two things and not sure if one or the other worked independently or you need to do both together.
1. ENABLE SMOOTH SCROLLING (see how to do it at this link)
http://ccm.net/faq/14877-firefox-how...ooth-scrolling
2. DISABLE HARDWARE ACCELERATION (see how to do it at this link)
https://ttboj.wordpress.com/2013/04/...ng-in-firefox/
Massive difference. If you're having issues and use the fix above, please reply back if it worked for you.
