Well I made another yahoo account and sent them a mail, saying I got h4c|<7d... Also I told them the account name, security questions and answers, when I made the account, when it got h4c|<7d, etc (pretty much everything you told me to do Don). Then, they sent me a couple of mails back, asking for different stuff (like security question no.1, no.2...) and each time I replied to that, they told me the answer was wrong. After telling them the dude changed the answers, they just sent me a new password.
Getting the IMVU account was easy. Just clicked on "forgot password" and they sent me a new one.
But that's just my case and I don't know if it would help others much.
Glad to help anyway!