Ubuntu 11.04 has many known issues posted on, one line said:
On certain systems, a bad interaction between Unity, the GL driver and the kernel may cause the system to hang. ()
This is a frequent screen frozen issue, and it’s said has something to do with the kernel. Default kernel come with Ubuntu 11.04 is 2.6.38-8, and here’s how to upgrade to Linux kernel 2.6.39-0.
Update: Kernel-ppa currently is down, there’s no kernel packages. Before adding the ppa check http://kernel.ubuntu.com/~kernel-ppa/mainline/. As an alternative, you can download latest kernel packages from
Press Ctrl+Alt+T to start a terminal window, and do following steps:
1.) Add the kernel ppa and update your system:
sudo add-apt-repository ppa:kernel-ppa/ppa sudo apt-get update
2.) Check available kernels with the command:
apt-cache showpkg linux-headers
kernel 22.214.171.124 should be in list.
3.) Run the command to install kernel 126.96.36.199:
sudo apt-get install linux-headers-2.6.39-0 linux-headers-2.6.39-0-generic linux-image-2.6.39-0-generic --fix-missing
Finally, reboot and check kernel version under System Monitor -> System tab.