First of all, make sure you have set the correct user to "no restrictions".
If you are still getting redirected:
This action could be caused by your browser's cache settings. When you switched to filtered access, your browser was given a 'redirect command' in an HTML page by ContentBarrier. Your browser has now placed this page in its 'cache', and rather than reload the page from the Internet, it reads the page from its cache files on the hard drive, which is the page that tells it to redirect to Yahooligans.
In Safari, there is an "Empty Cache" command under the "Safari" menu at the top of the screen. Use this to remove the cached pages.
In Internet Explorer's preferences is a section for the cache settings. This is usually under Web Browser -> Advanced, but may vary depending on the version you are using. Here you will find a button to 'Empty the Cache', this will solve this problem this time. It will be better to also make the 'Update Pages:' setting either 'Once per session' or 'Always'. This way the cached page files will be updated at least when you relaunch IE if set to Once per session, or IE will not rely on the cache at all for page files if set to Always.
The cache feature of browsers was developed as a way to speed Internet access at a time when most users were using slow dial-up access. If the browser could read the files from the hard drive rather wait for a download each time a page was asked for, it would appear much faster.