I have my website live on Cent Os Server Apache 2.2.15. Developed on PHP Codeigniter.
I get Forbidden error for the 1st time as I visit the website.
But then as I refresh it goes away and the page is loaded perfectly.
This happens to random users and not for everyone.
For some the site runs smoothly without any error.
For me it looks like a configuration difference between those two servers. Make sure that both servers have exactly the same: