I noticed that after turning off the option to automatically add comments, plugin continues to look for new comments. This leads to a heavy load on the server thing found my support act after consideration of my server.

2013-04-28 09:10:41] – [Comments Import] [ALL] – Checking for new comments now… Array ( [0] => 26379 )
[2013-04-28 08:10:40] – [Comments Import] [ALL] – Checking for new comments now… Array ( [0] => 26379 )
[2013-04-28 07:10:42] – [Comments Import] [ALL] – Checking for new comments now… Array ( [0] => 26379 )
[2013-04-28 06:10:41] – [Comments Import] [ALL] – Checking for new comments now… Array ( [0] => 26379 )
[2013-04-28 05:10:41] – [Comments Import] [ALL] – Checking for new comments now… Array ( [0] => 26379 )
[2013-04-28 04:10:40] – [Comments Import] [ALL] – Checking for new comments now… Array ( [0] => 26379 )
[2013-04-28 03:10:40] – [Comments Import] [ALL] – Checking for new comments now… Array ( [0] => 26379 )
[2013-04-28 02:10:44] – [Comments Import] [ALL] – Checking for new comments now… Array ( [0] => 26379 )
[2013-04-28 01:10:42] – [Comments Import] [ALL] – Checking for new comments now… Array ( [0] => 26379 )
[2013-04-28 00:10:41] – [Comments Import] [ALL] – Checking for new comments now… Array ( [0] => 26379 )
[2013-04-28 00:10:40] – [Comments Import] [ALL] – Checking for new comments now… Array ( [0] => 26379 )

I use Facebook comments, not those of WordPress.
Thanks