i had the same issue as the previous two posters, if i did sudo dpkg-reconfigure udev, it only updated the -9-rt kernel, and not the -14-generic kernel, i fixed it by running:
sudo dpkg-reconfigure udev sudo update-initramfs -u -k 2.6.31-14-generic
this fixed the problem, so i beleve that udev is not configured to reconfigure the initramfs on the new kernels.
i had the same issue as the previous two posters, if i did sudo dpkg-reconfigure udev, it only updated the -9-rt kernel, and not the -14-generic kernel, i fixed it by running:
sudo dpkg-reconfigure udev
sudo update-initramfs -u -k 2.6.31-14-generic
this fixed the problem, so i beleve that udev is not configured to reconfigure the initramfs on the new kernels.