Problems displaying web pages

Hi,

I've been encountering problem with viewing certain websites and pages on Safari. It is my default browser on my Retina Display 15-inch Macbook, but I also tried using Chrome and still have the same problem.

Basically, sometimes the whole webpage cannot be displayed and I get an error message saying either "can't connect to server" or "the server dropped the connection". Sometimes, the page loads but it's empty. White screen only.
Other times, the page loads, but it is messed up and looks like this:

Different websites show different weird loading problems.I tried deleting cookies and reseting Safari but to no avail. How can I fix this?