I've imported my old database (via phpMyAdmin) and everything seemed to be fine - except for the user/password combinations. I tried to do a "FLUSH PRIVILEGES" and afterwards, I couldn't login anymore into my root account either (which was working).
I tried to reset it via stopping the mysqld, starting mysqld_safe with the --skip-grant-tables flag and reset the root password. It returned no error message, but when I tried to login I still got 'Access denied'.
Any idea of what might have gone wrong?
Thanks a lot!
PS: This is on a Debian 5.0.6 System
EDIT: Somehow my root account was gone. I had to repeat the steps again, reset all the other passwords in the mysql.user table and add a new root account via
mysql> INSERT INTO user VALUES ('localhost','root',password('newpass'),'Y','Y ','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y', 'Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','' ,'','','',0,0,0,0);
mysql> INSERT INTO user VALUES ('127.0.0.1','root',password('newpass'),'Y','Y ','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y', 'Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','' ,'','','',0,0,0,0);
Now it's working again.
Thanks for all the replies! Cheers