Error_log - Error de programador o error de Servidor

[Da Vinci]

Hola maestros, tengo el siguiente problema, cada vez que alguien visita mis sitios, se genera este archivo error_log, el cual tienen el siguiente contenido...

[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_connect in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_pconnect in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_close in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_select_db in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_query in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_fetch_batch in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_rows_affected in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_free_result in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_get_last_message in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_num_rows in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_num_fields in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_fetch_field in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_fetch_row in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_fetch_array in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_fetch_assoc in Unknown on line 0
[06-Sep-2007 23:34:29] PHP Warning: Function registration failed - duplicate name - mssql_fetch_object in Unknown on line 0

Esto es solo parte del mismo, el archivo que se genera cada vez crece y crece....

Mi pregunta es si este archivo de error se genera por error del programador o por error del servidor...Ojo, que mis aplicacion funcionan correctamente, antes no tenia este problema, Muchas gracias por vuestras sugerencias