When I give one quick tap of brightness up using the laptop keyboard (Fn + Arrow up), I see the following:

The bug also happens when switched to a virtual console with CTRL-ALT-F1. while optirun glxgears is running) or off. The bug happens regardless on whether the nvidia card is on (i.e. In both cases optimus was ON in the bios, but in the former case the system was falling back unity2D (I believe), and after installing bumblebee it uses unit圓D (though always with the intel card). This happened both with a fresh installation, and after installing bumblebee. I have a Dell E6520 with Intel+NVidia (optimus). UpgradeStatus: No upgrade log present (probably fresh install)ĭmi.modalias: dmi:bvnDellInc. ProcKernelCmdLine: BOOT_IMAGE= /boot/vmlinuz- 2.6.38- 11-generic root=UUID= 0dfaacc9- c19d-425b- 963d-dabb87ae18 bc ro quiet splash vt.handoff=7 InstallationMedia: Ubuntu 11.04 'Natty Narwhal' - Release amd64 (20110427) Package: gnome-power-manager 2.32.0-2ubuntu2.1

Reinstalled the OS twice, but not because of this issue and the problem seems to persist. The CPUs don't seem to go to 100%, but the adjustment process seems relatively slow. Changing the brightness via FN key combination or via the brightness applet is very slow.