Did it say "You have been logged off, cause you have logged onto another machine" ? It sounds like either someone stole your password an logged you off, or they booted you, then locked up your account so you couldn't sign back in. The first thing you need to do here is figure out exactly what happened, what happens when most people lose their ids is they don't try and figure out what happened, which is the logical thing to do, i understand most people dunno ne ways at all how ids are stolen. I would goto
www.my.yahoo.com and try to log the id in. If your id was stolen you should be able to recover it, if not thru password lookup, you can contact yahoo! But if you don't remember the information you put on the account(different then your actual info "bogus info") You cannot recover the account, unless you can remember exactly what it was. Go here:
http://edit.yahoo.com/config/eval_forgot_pw
Were it says: Your Birthday - put in your birthday
Your Zip(or Postal) Code - put in your zipcode
Your Country or Territory - put in your country
2. Forgot your password?
Enter your Yahoo! ID - put your id right there
Then press the button GET NEW Password
If the info is correct it will take you to your secret question. If its not right then it will say "You must match the information stored in your Yahoo! account." If you get to the secret question try to answer it, an it also might have a button to email yourself a new password, if u know for sure your email is on the account and u have access to it, then email yourself a new pw if u can't answer the question. And if your account is terminated(deactivated) it will tell you that instead of refreshing the pw look up screen. Lemme know