Windows Live mail 2011 Deleted credentials

A strange one, this. I've been using the Windows Live 2011 client to read Yahoo mail. I have not been logging in with a Live ID, and apparently, WLM puts it's own credentials in the saved credentials in W7. I deleted those details and now can't see the contacts that were built up offline for Yahoo, it keeps asking for credentials. These credentials are a random number, and a password that I never saw.

Anyone got any idea how to recover these credentials?