Option of sources.ini multi_insert_step not working

[Ivinco]

Option of sources.ini multi_insert_step not working with value 1000.
With this option i got MySQL server has gone away each time I run php indexer.php myidx

[Ivinco (info-ivinco)]

my source.ini

[rt_2_000_000]
; some straightforward parameters for MySQL source type
sql_host = localhost
sql_user = root
sql_pass =
sql_db = mydb
sql_port = 3306 ; optional, default is 3306

; some straightforward parameters for Sphinx connection
sphinx_host = 127.0.0.1
sphinx_index = rt_2_000_000
sphinx_port = 9306 ; optional, default is 9306

; how much records will be inserted per query into real time index
; 0 - do not use multi inserts
multi_insert_step = 1000

sql_query = "SELECT id, title, body, is_post, is_page, post_type, date_added
                     FROM rt_2_000_000
                     WHERE id>=$start and id<$end"

sql_query_range = "SELECT min(id) , 2000000 FROM rt_2_000_000"

sql_range_step = 1000

When I run indexer, I got next output
yaroslav@book:~/sphinxtests/scripts$ php indexer.php rt_2_000_000
In Range: 1 - 1001
MySQL server has gone away