Ubuntu :: Copied Kubuntu To New Partition But Now Boots To Old Partition?

I'm trying to copy kubuntu from a old disk to a partition on a new hard disk. I used the command:

cp -apx /mnt/source /mnt/dest

I also edited fstab and changed the uuid to the correct partition, rebuild grub, and rebooted. When booting the kubuntu in the new partition, the sysytem still refers to the old partition (which is much smaller). ie: df displays the old partition. Is there another config file that has to be edited?