How to downgrade Kernel

It seems that I have been affected by power regression bug. I am using Ubuntu 11.10. I want to know is there any harm in downgrading to a kernel that does not have this bug. How to downgrade the Kernel? Is http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.39.1-oneiric/ kernel suitable for this purpose.

why dont you try upgrading the kernel to 3.1.0 to remove the bug.

Donwloading from the Mainline the linux-image-3.1.0-030100rc10-generic. Installing it. Rebooting with it and the ubuntu 11.10 is running with the 3.1.

http://www.howopensource.com/2011/08/how-to-install-linux-kernel-3-1-rc2-oneiric-in-ubuntu-11-04-10-10-and-10-04/

                             if you want to downgrade

Ubuntu Packages Search: http://packages.ubuntu.com

Picking natty-updates kernel linux-image-2.6.38-10-generic : http://packages.ubuntu.com/natty-updates/linux-image

Downloading it and installing with the command:

sudo dpkg -i linux-image-2.6.38-10-generic_2.6.38-10.46_i386.deb

reboot.