mysql crash IMPORTANT

[comby]

hello,

I have a big problem, all few hours my mysql daemon crashs. Its totally random. I already changed alot in the config, but it cant be fixed so far

here the mysqld.err log

mysqld process hanging, pid 22747 - killed 
mysqld process hanging, pid 22747 - killed 
mysqld process hanging, pid 22747 - killed 
040225 12:53:38  mysqld restarted 
Warning: Ignoring user change to 'mysql' because the user was set to 'mysql' earlier on the command line 
040225 12:53:38  Can't start server: Bind on TCP/IP port: Address already in use 
040225 12:53:38  Do you already have another mysqld server running on port: 3306 ? 
040225 12:53:38  Aborting 

040225 12:53:38  /usr/sbin/mysqld: Shutdown Complete 

040225 12:53:38  mysqld ended

Here my mysql config (my.cnf)

[client] 
#password       = my_password 
port            = 3306 
socket          = /var/run/mysqld/mysqld.sock 

[safe_mysqld] 
err-log         = /var/log/mysql/mysql.err 

[mysqld] 
skip-innodb 
user            = mysql 
pid-file        = /var/run/mysqld/mysqld.pid 
socket          = /var/run/mysqld/mysqld.sock 

basedir         = /usr 
datadir         = /var/lib/mysql 
tmpdir          = /tmp 
language        = /usr/share/mysql/english 
skip-locking 
set-variable    = key_buffer=16M 
set-variable    = max_allowed_packet=1M 
set-variable    = thread_stack=128K 
set-variable    = key_buffer=16M 
set-variable    = max_allowed_packet=1M 
set-variable    = thread_stack=128K 
set-variable    = table_cache=64 
set-variable    = sort_buffer=512K 
set-variable    = net_buffer_length=8K 
set-variable    = myisam_sort_buffer_size=8M 
set-variable    = query_cache_size=12M 
set-variable    = max_connections=400 
set-variable    = wait_timeout=90 
set-variable    = interactive_timeout=90 
set-variable    = max_connect_errors=999999 
set-variable    = max_delayed_threads=999999 

# keep secure by default! 
bind-address    = 127.0.0.1 
port            = 3306 
# this can make it even more secure: 
#skip-networking 

[mysqldump] 
quick 
set-variable    = max_allowed_packet=1M 

[mysql] 
#no-auto-rehash # faster start of mysql but no tab completition 

[isamchk] 
set-variable    = key_buffer=16M

I am open for everything, please reply if you have ANY idea.

thanks alot