Sorry, I tried to look for a solution but could not succeed.
here is part of daemon.log:

Jul  2 10:26:51 maison-desktop mysqld_safe[722]: 090702 10:26:51 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:26:51 maison-desktop mysqld_safe[722]: 090702 10:26:51 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:26:51 maison-desktop mysqld_safe[722]: ERROR: 1005  Can't create table 'db' (errno: 13)
Jul  2 10:26:51 maison-desktop mysqld_safe[722]: 090702 10:26:51 [ERROR] Aborting
Jul  2 10:26:51 maison-desktop mysqld_safe[722]: 
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: 090702 10:26:52 [Note] /usr/sbin/mysqld: Shutdown complete
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: 
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: Installation of system tables failed!
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: 
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: Examine the logs in /home/mysql for more information.
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: You can try to start the mysqld daemon with:
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: /usr/sbin/mysqld --skip-grant &
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: and use the command line tool
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: /usr/bin/mysql to connect to the mysql
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: database and look at the grant tables:
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: 
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: shell> /usr/bin/mysql -u root mysql
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: mysql> show tables
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: 
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: Try 'mysqld --help' if you have problems with paths. Using --log
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: gives you a log in /home/mysql that may be helpful.
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: 
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: The latest information about MySQL is available on the web at
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: http://www.mysql.com
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: Please consult the MySQL manual section: 'Problems running mysql_install_db',
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: and the manual section that describes problems on your OS.
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: Another information source is the MySQL email archive.
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: Please check all of the above before mailing us!
Jul  2 10:26:52 maison-desktop mysqld_safe[722]: And if you do mail us, you MUST use the /usr/bin/mysqlbug script!
Jul  2 10:26:52 maison-desktop mysqld_safe[763]: 090702 10:26:52 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:26:52 maison-desktop mysqld_safe[763]: 090702 10:26:52 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:26:52 maison-desktop mysqld_safe[763]: ERROR: 1146  Table 'mysql.user' doesn't exist
Jul  2 10:26:52 maison-desktop mysqld_safe[763]: 090702 10:26:52 [ERROR] Aborting
Jul  2 10:26:52 maison-desktop mysqld_safe[763]: 
Jul  2 10:26:52 maison-desktop mysqld_safe[763]: 090702 10:26:52 [Note] /usr/sbin/mysqld: Shutdown complete
Jul  2 10:26:52 maison-desktop mysqld_safe[763]: 
Jul  2 10:26:52 maison-desktop mysqld_safe[774]: 090702 10:26:52 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:26:52 maison-desktop mysqld_safe[774]: 090702 10:26:52 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:26:52 maison-desktop mysqld_safe[774]: ERROR: 1146  Table 'mysql.user' doesn't exist
Jul  2 10:26:52 maison-desktop mysqld_safe[774]: 090702 10:26:52 [ERROR] Aborting
Jul  2 10:26:52 maison-desktop mysqld_safe[774]: 
Jul  2 10:26:52 maison-desktop mysqld_safe[774]: 090702 10:26:52 [Note] /usr/sbin/mysqld: Shutdown complete
Jul  2 10:26:52 maison-desktop mysqld_safe[774]: 
Jul  2 10:26:52 maison-desktop mysqld_safe[781]: 090702 10:26:52 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:26:52 maison-desktop mysqld_safe[781]: 090702 10:26:52 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:26:52 maison-desktop mysqld_safe[781]: ERROR: 1146  Table 'mysql.user' doesn't exist
Jul  2 10:26:52 maison-desktop mysqld_safe[781]: 090702 10:26:52 [ERROR] Aborting
Jul  2 10:26:52 maison-desktop mysqld_safe[781]: 
Jul  2 10:26:52 maison-desktop mysqld_safe[781]: 090702 10:26:52 [Note] /usr/sbin/mysqld: Shutdown complete
Jul  2 10:26:52 maison-desktop mysqld_safe[781]: 
Jul  2 10:26:53 maison-desktop mysqld_safe[789]: 090702 10:26:53 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:26:53 maison-desktop mysqld_safe[789]: 090702 10:26:53 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:26:53 maison-desktop mysqld_safe[789]: ERROR: 1046  No database selected
Jul  2 10:26:53 maison-desktop mysqld_safe[789]: 090702 10:26:53 [ERROR] Aborting
Jul  2 10:26:53 maison-desktop mysqld_safe[789]: 
Jul  2 10:26:53 maison-desktop mysqld_safe[789]: 090702 10:26:53 [Note] /usr/sbin/mysqld: Shutdown complete
Jul  2 10:26:53 maison-desktop mysqld_safe[789]: 
Jul  2 10:26:56 maison-desktop AppArmor(init): Skipping profile /etc/apparmor.d/usr.sbin.mysqld~
Jul  2 10:27:01 maison-desktop mysqld_safe[977]: started
Jul  2 10:27:01 maison-desktop mysqld[981]: 090702 10:27:01 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:27:01 maison-desktop mysqld[981]: 090702 10:27:01 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:27:01 maison-desktop mysqld[981]: 090702 10:27:01  InnoDB: Operating system error number 13 in a file operation.
Jul  2 10:27:01 maison-desktop mysqld[981]: InnoDB: The error means mysqld does not have the access rights to
Jul  2 10:27:01 maison-desktop mysqld[981]: InnoDB: the directory.
Jul  2 10:27:01 maison-desktop mysqld[981]: InnoDB: File name ./ibdata1
Jul  2 10:27:01 maison-desktop mysqld[981]: InnoDB: File operation call: 'create'.
Jul  2 10:27:01 maison-desktop mysqld[981]: InnoDB: Cannot continue operation.
Jul  2 10:27:01 maison-desktop mysqld_safe[996]: ended
Jul  2 10:27:17 maison-desktop /etc/init.d/mysql[1146]: 0 processes alive and '/usr/bin/mysqladmin --defaults-file=/etc/mysql/debian.cnf ping' resulted in
Jul  2 10:27:17 maison-desktop /etc/init.d/mysql[1146]: ^G/usr/bin/mysqladmin: connect to server at 'localhost' failed
Jul  2 10:27:17 maison-desktop /etc/init.d/mysql[1146]: error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)'
Jul  2 10:27:17 maison-desktop /etc/init.d/mysql[1146]: Check that mysqld is running and that the socket: '/var/run/mysqld/mysqld.sock' exists!
Jul  2 10:27:17 maison-desktop /etc/init.d/mysql[1146]: 
Jul  2 10:31:01 maison-desktop AppArmor(init): Skipping profile /etc/apparmor.d/usr.sbin.mysqld~
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: 090702 10:33:02 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: 090702 10:33:02 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: ERROR: 1005  Can't create table 'db' (errno: 13)
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: 090702 10:33:02 [ERROR] Aborting
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: 
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: 090702 10:33:02 [Note] /usr/sbin/mysqld: Shutdown complete
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: 
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: Installation of system tables failed!
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: 
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: Examine the logs in /home/mysql for more information.
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: You can try to start the mysqld daemon with:
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: /usr/sbin/mysqld --skip-grant &
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: and use the command line tool
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: /usr/bin/mysql to connect to the mysql
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: database and look at the grant tables:
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: 
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: shell> /usr/bin/mysql -u root mysql
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: mysql> show tables
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: 
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: Try 'mysqld --help' if you have problems with paths. Using --log
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: gives you a log in /home/mysql that may be helpful.
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: 
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: The latest information about MySQL is available on the web at
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: http://www.mysql.com
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: Please consult the MySQL manual section: 'Problems running mysql_install_db',
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: and the manual section that describes problems on your OS.
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: Another information source is the MySQL email archive.
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: Please check all of the above before mailing us!
Jul  2 10:33:02 maison-desktop mysqld_safe[6057]: And if you do mail us, you MUST use the /usr/bin/mysqlbug script!
Jul  2 10:33:02 maison-desktop mysqld_safe[6095]: 090702 10:33:02 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:33:02 maison-desktop mysqld_safe[6095]: 090702 10:33:02 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:33:02 maison-desktop mysqld_safe[6095]: ERROR: 1146  Table 'mysql.user' doesn't exist
Jul  2 10:33:02 maison-desktop mysqld_safe[6095]: 090702 10:33:02 [ERROR] Aborting
Jul  2 10:33:02 maison-desktop mysqld_safe[6095]: 
Jul  2 10:33:02 maison-desktop mysqld_safe[6095]: 090702 10:33:02 [Note] /usr/sbin/mysqld: Shutdown complete
Jul  2 10:33:02 maison-desktop mysqld_safe[6095]: 
Jul  2 10:33:03 maison-desktop mysqld_safe[6110]: 090702 10:33:03 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:33:03 maison-desktop mysqld_safe[6110]: 090702 10:33:03 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:33:03 maison-desktop mysqld_safe[6110]: ERROR: 1146  Table 'mysql.user' doesn't exist
Jul  2 10:33:03 maison-desktop mysqld_safe[6110]: 090702 10:33:03 [ERROR] Aborting
Jul  2 10:33:03 maison-desktop mysqld_safe[6110]: 
Jul  2 10:33:03 maison-desktop mysqld_safe[6110]: 090702 10:33:03 [Note] /usr/sbin/mysqld: Shutdown complete
Jul  2 10:33:03 maison-desktop mysqld_safe[6110]: 
Jul  2 10:33:03 maison-desktop mysqld_safe[6117]: 090702 10:33:03 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:33:03 maison-desktop mysqld_safe[6117]: 090702 10:33:03 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:33:03 maison-desktop mysqld_safe[6117]: ERROR: 1146  Table 'mysql.user' doesn't exist
Jul  2 10:33:03 maison-desktop mysqld_safe[6117]: 090702 10:33:03 [ERROR] Aborting
Jul  2 10:33:03 maison-desktop mysqld_safe[6117]: 
Jul  2 10:33:03 maison-desktop mysqld_safe[6117]: 090702 10:33:03 [Note] /usr/sbin/mysqld: Shutdown complete
Jul  2 10:33:03 maison-desktop mysqld_safe[6117]: 
Jul  2 10:33:03 maison-desktop mysqld_safe[6125]: 090702 10:33:03 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:33:03 maison-desktop mysqld_safe[6125]: 090702 10:33:03 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:33:03 maison-desktop mysqld_safe[6125]: ERROR: 1046  No database selected
Jul  2 10:33:03 maison-desktop mysqld_safe[6125]: 090702 10:33:03 [ERROR] Aborting
Jul  2 10:33:03 maison-desktop mysqld_safe[6125]: 
Jul  2 10:33:03 maison-desktop mysqld_safe[6125]: 090702 10:33:03 [Note] /usr/sbin/mysqld: Shutdown complete
Jul  2 10:33:03 maison-desktop mysqld_safe[6125]: 
Jul  2 10:33:05 maison-desktop AppArmor(init): Skipping profile /etc/apparmor.d/usr.sbin.mysqld~
Jul  2 10:33:07 maison-desktop mysqld_safe[6310]: started
Jul  2 10:33:07 maison-desktop mysqld[6314]: 090702 10:33:07 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:33:07 maison-desktop mysqld[6314]: 090702 10:33:07 [Warning] Can't create test file /home/mysql/maison-desktop.lower-test
Jul  2 10:33:07 maison-desktop mysqld[6314]: 090702 10:33:07  InnoDB: Operating system error number 13 in a file operation.
Jul  2 10:33:07 maison-desktop mysqld[6314]: InnoDB: The error means mysqld does not have the access rights to
Jul  2 10:33:07 maison-desktop mysqld[6314]: InnoDB: the directory.
Jul  2 10:33:07 maison-desktop mysqld[6314]: InnoDB: File name ./ibdata1
Jul  2 10:33:07 maison-desktop mysqld[6314]: InnoDB: File operation call: 'create'.
Jul  2 10:33:07 maison-desktop mysqld[6314]: InnoDB: Cannot continue operation.
Jul  2 10:33:07 maison-desktop mysqld_safe[6320]: ended
Jul  2 10:33:22 maison-desktop /etc/init.d/mysql[6479]: 0 processes alive and '/usr/bin/mysqladmin --defaults-file=/etc/mysql/debian.cnf ping' resulted in
Jul  2 10:33:22 maison-desktop /etc/init.d/mysql[6479]: ^G/usr/bin/mysqladmin: connect to server at 'localhost' failed
Jul  2 10:33:22 maison-desktop /etc/init.d/mysql[6479]: error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)'
Jul  2 10:33:22 maison-desktop /etc/init.d/mysql[6479]: Check that mysqld is running and that the socket: '/var/run/mysqld/mysqld.sock' exists!
Jul  2 10:33:22 maison-desktop /etc/init.d/mysql[6479]: