my system cant open some websites that it used to open before i ran the software update

I had the OS X v10.8.3 update pop up and i ran the update. Before then, i had access to all the websites but now i ralised some websites cant open e.g my twitter login on this mac doesnt get to log me in, cant open asos website, the most annoying aspect is that i'm actually developing my website via wix.com but evresince i ran the software update, the editor page of the website via wix just never loads. Initially i thought it was my browser,home network, then i went to the office and tried opening the wix editor html5 on the imac, running on OS X v10.7. and it was same experience. I went further to try opening the wix editor html5 on another desktop in the office windows 7 and it opened. only then did i come to a conclusion that it must be the operating system that is the cause of this. PLEASE PLEASE PLEASE HELP ME OUT...