Hi Maria,
The kernel mesg. { DriveReady SeekComplete DataRequest Error } means that
you have a physical error on your disk and it is unrecoverable.
So...
First of all, backup your data.
Then replace your hda disk. It's already crashed and will kill all your data
(soon or later)
Trash this disk.
Good luck ;-)
Ricardo 'j0k3r' Dalceno