Just found out the reason... If you have Avast Antivirus, the latest update interferes with Opera page loading in a big way. It also affects normal software loading times. There seem to be quite a few complaints about it. If you are having the same problems I was having, it seems the only option is to get rid of Avast as they are claiming the update makes your internet connection more secure. Personally I'm not up for waiting 10-12 seconds for pages to load. I've switched to Sophos Antivirus and the problem is gone. You could wait to see if either Opera or Avast try to fix the issue but there's no sign of either acknowledging the problem so far.