User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b2) Gecko/20081201 Firefox/3.1b2 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b2) Gecko/20081201 Firefox/3.1b2 Smooth scrolling isn't working properly after upgrading to FF 3.1 Beta 2. It looks like disabled when you use arrow keys, PgUp, PgDn or scroll bar for scrolling. It works properly when you use mouse wheel for scrolling. Reproducible: Always Steps to Reproduce: 1. enable smooth scrolling 2. go to some long web page 3. use PgDn, PgUp for scrolling Actual Results: Scrolling is not smooth. Expected Results: Smooth scrolling.