Shoutbox

A while ago, I opened sharing folders with one of my contacts so he could give me some pictures. Now that contact changed his address so he doesn't sign in from the one we had created the folders with. However, the sharing folders file is created in My Documents every time I sign in to Messenger. I have deleted his address and blocked it but no result. I checked in the Messenger options, in the tab with the sharing folders but the list with the contacts supposed to have a sharing folder with me was empty as it should, since I have no sharing folders with anyone else. I want to stop it from creating the same file every time I sign in to Messenger. Is there a way to do it?