Example my.cnf for 4.0.X

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
set-variable = key_buffer_size=160M
set-variable = join_buffer_size=64M
set-variable = max_allowed_packet=8M
set-variable = table_cache=256K
set-variable = sort_buffer_size=128M
set-variable = net_buffer_length=256K
set-variable = myisam_sort_buffer_size=128M
set-variable = read_buffer_size=8M
set-variable = long_query_time=5
set-variable = thread_cache_size=1M
set-variable = query_cache_size=8M
set-variable = read_rnd_buffer_size=32M
set-variable = tmp_table_size=64M
set-variable = record_buffer=4M
set-variable = log-slow-queries=/var/log/mysql_slow_queries.log
set-variable = long_query_time=3
set-variable = query_cache_type=1
set-variable = query_cache_size=256M
set-variable = query_cache_limit=4M
skip-innodb

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

[safe_mysqld]
err-log=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid