In my FTP system, I am using FileZilla.
So I change the transfer mode from ASCII to Auto.
That resolve all the errors.
I also wipe out all the wp-admin directory and related files (PLEASE BACKUP) and reinstall the whole wordpress 2.7.1 and deleted all the themes and plugins.
Plugins is sometimes the big killer in WordPress as it may crash with other plugins.
Hope that will help most people.