Network Error (tcp_error) A communication error oc

Question

Last days, I deployed a PHP app(ZF2) on a EC2 instance(Ubuntu Server 12.04).

I installed classic packages for a LAMP environment.

I defined my vhost then I test my website.

The website worked fine and sometimes I have the error :

Network Error (tcp_error) A communication error occurred: ""

I have no error. I checked Apache logs, PHP logs, etc but I found nothing why I have this error something.

When I reload the page, the page works again...

I would like to know if someone already got this case and can give me a way for resolve my issue.

Thanks