problem in some line error_log

Hello i see following line in this file: /usr/local/apache/logs/error_log i see daily thos line is creat, hoursly [QUOTE]2013-09-26 03:12:36.949 [INFO] [72.14.125.111:65281-0#APVH_user3.ir] File not found [/home/user3/public_html/404.s$ 2013-09-26 03:12:38.503 [INFO] [APVH_user6_Suphp:] pid list size: 2 2013-09-26 03:12:38.503 [INFO] [APVH_user6_Suphp:] add child process pid: 578580 2013-09-26 03:12:42.258 [INFO] [188.245.254.64:16963-0#APVH_n.user5.biz] File not found [/home/user5/public_html/fo$ 2013-09-26 03:12:42.258 [INFO] [188.245.254.64:16963-0#APVH_n.user5.biz] File not found [/home/user5/public_html/40$ 2013-09-26 03:12:43.525 [INFO] [APVH_user4_Suphp:] pid list size: 2 2013-09-26 03:12:43.525 [INFO] [APVH_user4_Suphp:] add child process pid: 578595 2013-09-26 03:12:45.192 [INFO] Remove pid: 578483 2013-09-26 03:12:45.192 [INFO] Pid: 578483 associated with [APVH_user3_Suphp:] 2013-09-26 03:12:45.192 [INFO] [APVH_user3_Suphp:] pid list size: 0, pid stop list size: 0 2013-09-26 03:12:45.192 [NOTICE] [APVH_user3_Suphp:] stop worker processes 2013-09-26 03:12:47.364 [INFO] Remove pid: 578361 2013-09-26 03:12:47.364 [INFO] Pid: 578361 associated with [APVH_user2_Suphp:] 2013-09-26 03:12:47.364 [INFO] [APVH_user2_Suphp:] pid list size: 0, pid stop list size: 0 2013-09-26 03:12:47.364 [NOTICE] [APVH_user2_Suphp:] stop worker processes 2013-09-26 03:12:50.366 [INFO] Remove pid: 578340 2013-09-26 03:12:50.366 [INFO] Pid: 578340 associated with [APVH_parsalva_Suphp:] 2013-09-26 03:12:50.366 [INFO] [APVH_user1_Suphp:] pid list size: 1, pid stop list size: 0
what i must do? Note1: my PHP 5 Handler is cgi Note2: Apache suEXEC: on Thanks.