I'm using Kubuntu 13.04 x64. I found out about this problem after installing Nvidia drivers from jockey and seeing that nouveau was still loading instead.
I tried to manually reinstall nvidia-current but initramfs-update fails:
$ update-initramfs: Generating /boot/initrd.img-3.8.0-23-generic E: /usr/share/initramfs-tools/hooks/fixrtc failed with return 1. update-initramfs: failed for /boot/initrd.img-3.8.0-23-generic with 1.
This errors started after trying to install Nvidia drivers, but it most probably is unrelated. As I understand from fixrtc, it's just trying to set the correct time using time, dumpe2fs and hwclock.
Can you tell me what's happening? I can't build initrd images with initramfs-tools failing on the fixrtc hook.