User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9b5) Gecko/2008032620 Firefox/3.0b5 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9b5) Gecko/2008032620 Firefox/3.0b5 When using CSS for a fixed background image, even if the image isn't of huge size (200KB) but a large resolution the vertical scrolling is very slow and stutters. Isn't a PC issue (Core 2 Duo, 4GB of ram), and performance is normal Reproducible: Always Steps to Reproduce: 1.Create page with fixed high res background (or go to URL provided) 2.Scroll with scroll wheel or side bar. 3. Actual Results: Scrolling was slow and stuttering, makes pages hard to view and use. Expected Results: Scrolling should have been like every page. Have noticed this in every FF3 beta.