Access denied for user 'root'@'localhost' in mysql

[Bernard Fay]

Hi,

I installed MySQL in Lenny.
When I try to login in with mysql -u root -p, I receive :

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using
password: YES)

I tried to reset the password of root by adding skip-grant-tables in my.cnf
then restart mysql.
I could login in with mysql -u root then I ran the following commands:

mysql> update user set password=password('password') where user='root';
mysql> flush privileges;


I removed skip-grant-tables from my.cnf and restarted mysqld.  I still have:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using
password: YES)

Any idea or clues about how to solve this issue?

Thanks,
Bernard