lol I exposed my self as a jackass long ago.

what does age have to do with shoulder surfing anyhow? its a very easy, very effective way of getting passwords done by many people both amature and pro. A LOT of people give passwords out.

as far as I know there have been no glitches with yahoo messenger that would give this error. There are numerous viruses out that use the messenger but they generally wont show you the message. I give the info that I did becasue like you said, I DONT KNOW YOU. you could be some dipshit 6 yearold on a computer in his school. If you changed your passwords and scanned your computer then good for you, you took the right first steps. if you are seriously concerned email yahoo and see if you can get the IP of the lat places it was signed in from (they probably wont giv this to you, but its worth a shot if you are seriously concerned)

breaking into yahoo/gmail/hotmail USED TO BE relativly easy, now it is much more complicated becasue they are far more aware of attempts and general security has gotten better (including time outs, failed attempt lockouts, etc. If someone is reading your email then they probably know you personnaly and have atleast some reason to want it. there is very little you can do at this point aside from playing defense and taking the steps you already have.

it sucks, but wait and see if it happens again. you said you changed your passwords, go and change the info like above (secret questions/alt email accounts) if you use standard passwords change them for everything that you used that password for.


edit**

after a bit of thought (no, really this time) it occurs to me that this type of error can occur if you get disconnected from the server (not signing off) and then trying to reconnect before the server times your account out and kicks it off. This can happen specificly in dial up situations becasue the IP address would have a high chance of being different so it would look like a new connection? but if it saying you logged in, it would a bit more difficult to pull this off. unless there was a server delay that held you as connect and then you reconnected it could show as a second connection, but that is sort of far reaching. just a thought though.