Windows Live Messenger Unknown User Online Bug

I've noticed that when I'm signed in, I will receive a random message in the bottom right corner stating that someone has just signed in. Unfortunatly, this is a bug considering that the user that signs in is not someone that is not a friend or is not even in my contact list in WLM. The Message will show the picture of the person but will not state the name of them. The Message reads " ... has just signed in" where " ..." is where the contacts name or handle should be. When I click on this to see if it will even open a conversation window so I can try chatting with that person "even though there not a contact of mine", I get an error stating something like "Windows Live Messenger Failed To Open The Conversation Window". I'm running Vista Business Service Pack 2 32Bit Edition. I work in the IT Field so I'm not computer illiterate and do know that I'm doing everything correctly to my knowledge, this error also seems to just happen at random. No events seem to be causing it to occur. I personally think it is a Windows Live Messenger Bug Compatability Issue With Vista Service Pack 2 Considering I just Installed Service Pack 2 Not Even A Week Ago And This Is When The Issue Started To Occur.

I am replying to my own post with an update. This error is very random, It did happen agian and I was able to get screen shots so I will be attaching them to this thread. I hope that someone may find a solution for it. I have blacked out parts of my screen for my own privacy. Note on attachment #1, the popup, attachment #2 is the error that I receive if I click the popup and attachment #3 is my system specs. Agian, I've never known this person and she's never been in my friends list. This is defenitly a bug with Windows Live Messenger and is quite possibly related to vista business service pack 2 x32 in regards to the service pack 2 upgrade.

Okay, I've had this same problem, and figured out the solution. I don't know if you'll ever see this again, but in hopes that someone googles this problem, here's what the problem was, at least with me - someone added me to a Windows Live group (I don't remember if I accepted an invitation or whether I received it at all) - after that, I was getting notifications for all the people from that group, whenever someone logged into Windows Live, even though they weren't my friend, and when I tried to click on the window, it gave the same error.

How I left the group - in the search bar in the contacts list, I searched for "a", "b", "c", etc. until the group was shown in the search results (it appears on the bottom of the results). Then right click, block group, and leave group. Also, all the members of the group were shown in the results when I searched through the search bar, but they were never displayed (and neither did the group) normally.

Hope you read this, I'll befriend you in hopes you'll get an email from this forum. Cheers!