Comment 5 for bug 182358

Your options are:
1) disable one of your two CPU cores (by passing maxcpus=1 to the kernel, for example. You can do this by editing your /boot/grub/menu.list file)
2) disable compiz.

Obviously I'd recommend disabling compiz if the lockups are too annoying.

Secondly, bugs are not the right place to ask questions - bugs are to inform the developers that something's wrong, and help them to find and fix it. Questions are more likely to be answered by using one of the support channels: «answers.launchpad.net/ubuntu» or «ubuntuforums.org».