It looks like the drive you are copying from has errors on it. If that is the case I wouldn't want to run off of it or a copy of it until you fix them (asuming they are fixable). Check the filesystem and the surface of the disks for bad blocks. How to do this depends on the filesystem.
Here is an excellent article on using dd: http://wiki.linuxquestions.org/wiki/Dd
It also talks about recovering media with errors on it. Note that it tells you to use 'conv=noerror' to keep copying even if you encounter errors. I would recommend against trying that until you first try to fix the errors because when dd encounters an error it fills the rest of the block the error was on with zeros. Who knows what kind of damage that could do.