optimize calls for admin.ajax file

Hi,
I am using CDN and I have been told the following about website speed:
Your origin server is failing to respond in timely manner when this file is requested from it:
– /wp-admin/admin-ajax.php?viberdata=&callback=jQuery110209362692104186863_1384187322520
and it’s been called two times so, what you can do is contact your developer and optimize calls for admin.ajax file as I am sure it’s not needed on each page.

I also noticed myself on http://tools.pingdom.com that admin-ajax.php and admin-ajax.php?viberjs=&i=734 have the same issue.

Is that something related to the theme.

Thanks.