MySQL is running but not working

In an attempt to tune MySQL to make it work with a recent installation of Drupal I had to modify the MySQL settings on my server. After modifying the configuration file for MySQL (/etc/my.cnf) MySQL stopped working. After some attempts I make it start again but now all my php/MySQL webistes are not being able to connect to their DBs.

Here is why is so confusing:

• If I check a phpinfo.php on any given site, the MySQL info is there
• phpmyadmin runs just fine
• I can run mysql from SSH using root but I see that mysql activity is reduced, look:

[root@server mysql]# mysqladmin processlist

+-----+-----------+-----------+-----------+----------------+------+--------------------+------------------+
| Id  | User      | Host      | db        | Command        | Time | State              | Info             |
+-----+-----------+-----------+-----------+----------------+------+--------------------+------------------+
| 7   | eximstats | localhost | eximstats | Sleep          | 30   |                    |                  |
| 103 | DELAYED   | localhost | eximstats | Delayed insert | 30   | Waiting for INSERT |                  |
| 104 | DELAYED   | localhost | eximstats | Delayed insert | 149  | Waiting for INSERT |                  |
| 105 | DELAYED   | localhost | eximstats | Delayed insert | 149  | Waiting for INSERT |                  |
| 119 | root      | localhost |           | Query          | 0    |                    | show processlist |
+-----+-----------+-----------+-----------+----------------+------+--------------------+------------------+

My websites using MySQL almost all say:

Error establishing a database connection

Another say:

Warning: mysql_connect() [function.mysql-connect]: Access denied for user 'website_USER'@'localhost' (using password: NO)

This is my current my.cnf:

[mysqld]
#datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
#pid-file=/var/lib/mysql/mysqld.pid
#skip-bdb
#skip-innodb
#err-log=/var/log/mysql.log
#bind-address = server.escalehost.com
log-bin = /var/lib/mysql/log-bin


#innodb_buffer_pool_size=2M
#innodb_additional_mem_pool_size=500K
#innodb_log_buffer_size=500K
#innodb_thread_concurrency=2
#max_connections=125
#table_cache=2500
#thread_cache_size=100
#thread_stack=250K
#wait_timeout=10
#join_buffer=5M
#myisam_sort_buffer_size=15M
#query_cache_size=15M
#read_rnd_buffer_size=5M
max_allowed_packet = 64M
#open_files_limit=8602

#[client]
#port           = 3306
#socket=/var/lib/mysql/mysql.sock

#[mysql.server]
#user=mysql
#basedir=/var/lib

[mysqld_safe]
#socket=/var/lib/mysql/mysql.sock
#err-log=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

I commented most of it to return it to its simplest version... How can I make the web side to connect to mysql?