Comment 28 for bug 123789

I updated to Gutsy from my 7.04 with all the patches applied and using the alternate CD. After the update the new kernel 2.6.22-14-generic hangs and I am only able to boot using the old 7.04 kernel 2.6.20-16-generic.

My Laptop is a Lenovo T60, Ubuntu is in a separate partition inside an extended one. This Laptop uses a new kind of partition table called GPT which is an Intel replacement for the outdated PC BIOS.
http://en.wikipedia.org/wiki/GUID_Partition_Table

I got the same booting problem with kernel 2.6.22 in Gentoo. It is a kernel bug.
Check http://gentoo-wiki.com/HARDWARE_IBM_ThinkPad_T60#Kernel_Configuration

File systems --->
  Partition Types --->
     [*] SGI partition support
     [*] EFI GUID Partition support

Hope this helps

Thanks for Ubuntu