Slow scrolling in Firefox on Fedora 12 - workaround
After upgrading to Fedora 12, I found that scrolling in Firefox was painfully slow. I'm using the Nouveau driver with a Geforce Go 5700 chip in my old 3.2 GHz Athlon64 laptop. Scrolling seemed to peg the CPU usage at 100% and render the computer unusable for the duration of the (very slow) scrolling.
Disabling "smooth scrolling" in the general section of the preferences seems to have fixed this.