Comment 389 for bug 272247

Same problem on Lenovo Ideapad S12 on clean install of 10.10
Booting with acpi_skip_timer_override solved the problem.

In /etc/default/grub I added
GRUB_CMDLINE_LINUX="acpi_skip_timer_override"

-BIOS-
Date : 05/13/2009
Vendor : LENOVO
Version : 19CN16WW
-Board-
Name : MoutCook
Vendor : LENOVO

-Processors-
Intel(R) Atom(TM) CPU N270 @ 1.60GHz : 800.00MHz
Intel(R) Atom(TM) CPU N270 @ 1.60GHz : 800.00MHz

-Version-
Kernel : Linux 2.6.35-22-generic (i686)
Compiled : #35-Ubuntu SMP Sat Oct 16 20:36:48 UTC 2010
C Library : GNU C Library version 2.12.1 (stable)
Default C Compiler : GNU C Compiler version 4.4.5 (Ubuntu/Linaro 4.4.4-14ubuntu5)
Distribution : Ubuntu 10.10
Desktop Environment : GNOME 2.32.0