Some strange things happening when I'm trying to use one or more of the web sites I usually visit. Why is that?
It could be that this is being caused by out-of-date information stored in your internet browser's cache. Web browsers temporarily store images and text from web pages on your hard drive in a storage area called a cache. Your browser's cache has information about webpages you've previously visited so that they'll load more quickly in the future. This works this way to help improve the time it takes to load web pages however it may cause problems when websites change. The steps you'll need to take to clear your browser's cache can be found in the article posted here.