For the second time I experienced a strange behaviour on my Ubuntu 10.04 box: some files are disappearing.
The first time happened with a NTFS partition on an external usb disk: "disk utility" told me that it had bad sectors in it and thus it was unreadable but, after a reformat of the disk, it was recognized succesfully.
The last time it happened with a ext4 partition: my home folder was almost completely wiped out; fortunately enough I use to store backups of my files, so I restored them but I can't figure out why I'm encountering those kind of situations.
So I assume that the problem is not really a matter of bad sectors (two different hard disks, that after the restore are working fine).
What am I supposed to do in order to debug/resolve the issue?
NOTE: the OS is a former Ubuntu Studio 9.10, upgraded to 10.04.