You should really perform a LEFT JOIN on the user table instead of a nested fetch_userinfo() call.
Why would you use $Entries['Date'] ... shouldn't it be $Entries['Author']. Also, I'm surprised your query even executes because 'Date' is a reserved MySQL keyword.
Add this debug code to the end of your loop
PHP Code:
var_dump($Entries);
var_dump($username342342342342); exit;
Finally, can you explain your logic behind it all? It's a bit confusing to me.