green artifact when clicking trash icon

Hi,
I have the same green artifact in left corner when I clicking any icon of gnome panel. This artifact appear when desktop effects are disabled.

nvidia 185.18.36
GeForce 8600M GT

Karmic Alpha5 installed
Linux 2.6.31-10-generic #32-Ubuntu SMP Thu Sep 10 23:29:56 UTC 2009 x86_64 GNU/Linux

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command, as it will automatically gather debugging information, in a terminal:

apport-collect 426449

This will help us to find and resolve the problem. Bear in mind that you may need to install the python-launchpadlib package from the universe repository. Additionally, when prompted to give apport-collect permissions for Launchpad you will need to give it at least the ability to "Change Non-Private" data as it will be adding information to your bug report. Thanks in advance!

When reporting bugs in the future please use apport, either via the appropriate application's "Help -> Report a Problem" menu or using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

Architecture: amd64
DistroRelease: Ubuntu 9.10
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release Candidate amd64 (20091020.3)
MachineType: Dell Inc. Inspiron 1720
NonfreeKernelModules: nvidia
Package: xorg 1:7.4+3ubuntu7
PackageArchitecture: amd64
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-14-generic root=UUID=e4abc9e7-d8f6-4864-939f-6b017549f734 ro quiet splash
ProcEnviron:
 SHELL=/bin/bash
 LANG=es_ES.UTF-8
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
RelatedPackageVersions:
 xserver-xorg 1:7.4+3ubuntu7
 libgl1-mesa-glx 7.6.0-1ubuntu4
 libdrm2 2.4.14-1ubuntu1
 xserver-xorg-video-intel 2:2.9.0-1ubuntu2
 xserver-xorg-video-ati 1:6.12.99+git20090929.7968e1fb-0ubuntu1
Uname: Linux 2.6.31-14-generic x86_64
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare
XsessionErrors:
 (gnome-settings-daemon:1750): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (gnome-settings-daemon:1750): GLib-CRITICAL **: g_propagate_error: assertion `src != NULL' failed
 (nautilus:1847): Eel-CRITICAL **: eel_preferences_get_boolean: assertion `preferences_is_initialized ()' failed
 (polkit-gnome-authentication-agent-1:1866): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed
dmi.bios.date: 07/11/2008
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A09
dmi.board.name: 0FP441
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA09:bd07/11/2008:svnDellInc.:pnInspiron1720:pvr:rvnDellInc.:rn0FP441:rvr:cvnDellInc.:ct8:cvr:
dmi.product.name: Inspiron 1720
dmi.sys.vendor: Dell Inc.
fglrx: Not loaded
system:
 distro: Ubuntu
 architecture: x86_64kernel: 2.6.31-14-generic