I am using Gentoo Linux with XFCE. Currently I have Firefox 9.0 but previous versions demonstrated the same behaviour.
Some pages, especially ones with lots of graphics when rendered look ok but very often when I scroll up or down part of the page just turns white. When I scroll that portion of the page out of view it reappears, although sometimes only partially. And then after a while disappears again.
Even though I would really like to but I don't expect to get a straight answer what to change in order to fix it, I would like to know where to start looking, what to change and what to test to try and solve this.
My machine has ATI Mobility Radeon HD 545v video card and I'm using drivers from ATI. I often update the system, OpenGL, X11 and video drivers included. This problem has been since I was using Kernel version 2, so I don't think it's a version specific issue.