Fedora 14 Windows garbled when moved or resized

[xaoslaad]

I am having a problem with a Fedora 14 guest on a Mac OS X 10.6 host running VirtualBox 4.0.0. This was happening in previous versions of Snow Leopard, VirtualBox, and Fedora. It seems that when windows are moved or resized they become garbled. Minimizing and restoring them restores the graphics, but it's pretty annoying and seems more frequent lately. 2D and 3D acceleration are disabled in the VM settings in Virtualbox and Desktop Effects are disabled; no compiz, etc. The two windows in the screenshot were garbled by simply moving them around. Does anyone have any idea how to fix this?

[dappawit]

I am having the exact same problem.

VirtualBox version: 4.0.6 (with guest additions)
guest: Fedora 14 x64
host: Windows 7 x64

Whenever I move a window in Fedora, the window becomes garbled--only the moved window, it doesn't affect other windows in Fedora. And, strangely, it seems to happen only when moving a window to the left, not to the right. And like the original poster, if I resize the garbled window, the glitches disappear (until I move the window again).

Has anyone else seen this problem? Does anyone have a suggestion as to how to fix it?
Thanks.

Edit:  For others with this problem, see the following: (1) http://www.virtualbox.org/ticket/8248 (2) https://bugzilla.redhat.com/show_bug.cgi?id=675257 The fix in (1) describing downgrading X11 also worked for me.