After upgrading to OS X 10.7.2 - the latest version of Lion - I started seeing corruption when I moved windows. It looked like images behind the window where bleeding into the window I was moving. When I clicked on a different window the corruption would disappear.
Some quick googling suggested that repairing my disk permissions might fix the issue.
So reboot into the "Recovery HD" (reboot and hold down the alt/option key as the boot process starts to display bootable drives), run "Disk Utitity" and run "Repair Permissions". Reboot.
Everything seems to be fixed...