MySQL corruption even after full dump and re-import
Paolo, can you please provide the mysql error log?  If one isn't available, you can add one by adding this line to your my.cnf file

[mysqld]

log-error=/var/log/mysql/mysql.err

One possible idea to narrow down your research.

You already know how to remove the ibdata and iblog files to create new ones.   If you just want to test your mysql installation.   


Remove the Innodb_force_recovery or comment it out
Backup your databases : mysqldump --all-databases -u root -p | gzip -9 &gt; all_databases.sql.gz
Move your MySQL data directory somewhere else: mv /var/lib/mysql{,.bak}
Create a new MySQL data directory: mkdir /var/lib/mysql
Give rights to the MySQL user: chown -R mysql:mysql /var/lib/mysql
Start MySQL: /etc/init.d/mysql start
Run a tail -f on the mysql log you added to my.cnf: tail -f /var/log/mysql/mysql.err


If MySQL isn't running then something else on the system level isn't right.  As Gopinath's link mentionned.  Is there enough disk space: df -h and inodes: df -i? Is you file system healthy? A system reboot or using fsck on the disk partition where MySQL is installed, would detect and possibly fix file system problems.  

If MySQL comes back, then you can restore your databases:

zcat all_databases.sql.gz | mysql -u root -p

Send us the logs after completing the steps I sent, and we'll take it from there.