Problem since most recent Norton Update Installed

This morning I rebooted my computer in response to the box that popped up from Norton 360 telling me there was an update that needed to be installed. Now I am having a problem with certain websites that will not load. The two I have noticed so far are vitals.com and healthgrade.com, both of which are healthcare review websites. I am currently in the process of researching surgeons and need to be able to access these websites. Yesterday I had no problem getting on them. Today they just hang saying “transferring data” but the sites never actually load. I normally use firefox but I also tried on IE without success. I am using Vista and my version of 360 is 21.6.0.32. I don’t know what the update was but it is whatever was sent around to be installed on 4/21/2015. Can someone please help me fix this problem. Something seems to be blocking my access to these websites. Thank you.