Client 'stuck' on website

Since upgrading to V2, I've had a user/client 'stuck' on my website as indicated by the latest visitor add on. Each time I refresh the page or do a little work, their page view increases the same as mine and always a minute behind, hence the blacklist query in other post as I'm wanting them gone. The I.P address and host are not mine. See attached screenshot, how do I get rid of them and why are they 'stuck' on the website ?

Thanks, Mark

If you look in the database do you and this other record have any data that is common or are they totally different.