The mlehworld avatars will be cached locally on your hard drive (saves downloading them every time you visit the webpage), hence the connection to 14 sites in one minute etc. That’s why your IT dept. thinks you’ve downloaded Dead polar bear pron!
Take a look in the internet cache it should be very colourful!!
Even if you deleted the internet cache within IE 7, index.dat holds a list of all the website you’ve ever been to!!!
that’s why I use Firefox!