Created attachment 30523 [details]
bugzilla.png - example of the submit-bug form rendering from bugs.freedesktop.org
Kernel 2.6.32-rc4, radeon driver from git as of 255ac8d54e3dc12e579e05edb41b40946a00eab8 (Oct 13 2009), libdrm-2.4.14 (with radeon pieces enabled), mesa-7.6.
Hardware is a built-in (on-motherboard) amd780g chipset.
The corruption is 100% reproduceable but not large. However for some applications it is larger and for some even makes the thing unusable.
On the attached bugzilla.png file the corruption is marked by red lines. It's obvious in the center of the "add comment" input field (the large horizontal black line) and at the end of this input field. It's less obvious but visible in the menu line of the window.
(I'll attach another example of the same thing, which is much more annoying than this).
Overall, the corruption always follows mouse, and it is possible to remove it (once on the screen) by just moving mouse over the corrupt areas. But depending on the direction of mouse movements this way may add even more corruptions.
It also happens when switching between windows.
Most common areas of corruption are the bottom of menu areas, bottom half of scrollbars, bottom of current menu item (bottom of highlighted area) in gnome memus and the like.
Created attachment 30524 [details]
corruption of kvm (qemu) window
Second example: the kvm/qemu window. The horizontal lines follows mouse if moving from bottom to top. The slower you move the mouse, the more lines will be there. Moving mouse from top to bottom _clears_ the corruption.
Just to be clear: while corruption follows the mouse pointer, it is not limited to mouse movements. For example, all menu corruptions happens without mouse involved initially. I can change the way how menus are not drawn completely by moving mouse over/near the corrupt areas.
*** This bug has been marked as a duplicate of bug 24430 ***