problem fixed after kernel update
william@frodo:~$ uname -a Linux frodo 2.6.24-16-generic #1 SMP Thu Apr 10 13:23:42 UTC 2008 i686 GNU/Linux
problem fixed after kernel update
william@frodo:~$ uname -a
Linux frodo 2.6.24-16-generic #1 SMP Thu Apr 10 13:23:42 UTC 2008 i686 GNU/Linux