Server Too Busy Problem

[necblog]

Hello
i have a server : Core2 Quad Q9400 + 8GB of ram which load average is about 0.20 and memory usage is about 5%
and i see this error : Server Is too busy at the moment please check back again
but i have some Security configs :
PHP safe_mod = on
disable_functions="link,symlink,readlink,ini_get,p hp_uname,exec,system,passthru,shell_exec,escapeshe llarg,escapeshellcmd,proc_close,proc_open,ini_alte r,dl,popen,curl_exec,popen,pcntl_exec,socket_accep t,socket_bind,socket_clear_error,socket_close,sock et_connect,socket_create_listen,socket_create_pair ,socket_create,socket_get_option,socket_getpeernam e,socket_getsockname,socket_last_error,socket_list en,socket_read,socket_recv,socket_recvfrom,socket_ select,socket_send,socket_sendto,socket_set_block, socket_set_nonblock,socket_set_option,socket_shutd own,socket_strerror,socket_write,stream_socket_cli ent,stream_socket_server,fsockopen,pfsockopen,stre am_set_timeout,disk_total_space,disk_free_space,ch own,getrusage,get_current_user,set_time_limit,getm yuid,getmypid,dl,leak,listen,chgrp,link,symlink,dl open,proc_nice,proc_get_stats,proc_terminate,shell _exec,sh2_exec,posix_getpwuid,posix_getgrgid,posix _kill,ini_restore,mkfifo,dbmopen,dbase_open,filepr o,filepro_rowcount,posix_mkfifo,putenv,sleep"


and some mod_sec configs do you think this is because of my PHP configs?

--------------- Added [DATE]1238223488[/DATE] at [TIME]1238223488[/TIME] ---------------

another thing server too busy page is not a vbulletin page it is a Blank page