Your site looks fine to me. I can open posts.

Try disabling or refreshing W3 Total Cache. It looks like this may be a caching issue.
I was also unable to reproduce a redirect via a CURL call.

Regards,
Russell Mitchell | Support Team

I was able to go to the following URL just fine: http://www.factoryunlockediphone4.com
While there, I clicked on a few hyperlinks and everything seemed to work as it's supposed to.

When I attempted to go to the following URL, directly, I got nothing but a white screen: http://www.factoryunlockediphone4.com/?action=dosignin

However, when I went to www.factoryunlockediphone4.com and THEN clicked on the "Sign In" link at the top-right of the homepage, I received a pop-up login screen.

What exactly is the problem you're having? Which "posts" are you clicking on that result in the error?

clear cache from your site and your browser also.