fglrx 8.801 generates video garbage in certain conditions on HD4290. Consider the attached screenshot: left panel is a autohiding gnome panel, whenever it slides out it is garbled. Also note some garbare near the bottom of the screen. Garbage may appear randomly on scrolling areas, window borders when they are moved or resized. Otherwise it works fine - video, everything.
ubuntu 10.10 32bit, MSI 890GXM-G65 motherboard with 890GX chipset and onboard HD4290,athlon II x2 255, not overclocked, sideport memory enabled, no problem with default X11 radeon drivers.