That will only happen if you visit the wiki via as it opens the wiki into an iframe within the main site. If you go to it won't do that and any links will open in a new window or tab in your browser.

BTW, we really need to get back into working on the wiki at some point soon. I've not touched it much in a long time. I did do a bot of work on some of the pages recently, but not too much. There is loads to do on the site and add. As soon as I get time I will begin again on adding content. I also want to develop the front page of it a lot to make it more friendly, and create a more contained look with content boxes showing links to each area, rather than just the current list.