Comment 12 for bug 422994

@JTZ, thanks for your logs and error report. Can you please:

1) also attach the similar output for the kernel 2.6.31 (or karmic) ?
2) It will be great if you could paste a bigger output of dmesg i.e messages before the error message as well.
3) Also try this:
    a) make this file (if it does not exist) in /etc/modprobe.d/options
    b) make/add an entry in it:
        options libata udma/100
    c) *copy* your current initramfs somewhere safe (in the event you fail, this will be needed)
    d) fire the following command to update your existing initramfs:
        update-initramfs -u
    e) reboot and get the output of hdparm -l /dev/sda and attach it here.
    f) test if your data copy works now with this new speed.