PHP MySQL error on valid query

I'm getting an error in PHP on a valid query, which executes fine when run directly from PHPMyAdmin.

Has anyone had a similar problem before and could point me in the right direction?

The error is below along with the function used the execute the query.

Array 
( 
    [Error] => Invalid Query : SELECT * FROM users ORDER BY userDeleted ASC, userFullname ASC 
) 
Array 
( 
    [Error] => Empty MySQL resource. 
) 

public function query($q){ 
        if(empty($q)) $this->dbError('Empty MySQL Query.'); 
        if($this->linkID == 0) $this->connect(); 
        $temp = @mysql_query($q, $this->linkID); 
        if(!$temp) $this->dbError('Invalid Query : '.mysql_error().'<br />'.$q); 
        return $temp; 

} 

public function getUsers(){ 
    $q = "SELECT * FROM users ORDER BY userDeleted ASC, userFullname ASC"; 
    $result = $this->query($q);  

Update: The database is connected to via:

private function connect(){
        if(!$this->linkID){
            $this->linkID = @mysql_connect(DB_HOSTNAME, DB_USERNAME, DB_PASSWORD);
            if(!$this->linkID) $this->dbError('Could not connect: ' . mysql_error());
            $this->select_db();
        }
        return $this->linkID;   
    }

    function select_db(){
        if($this->linkID){
            if(!@mysql_select_db(DB_NAME, $this->linkID)) $this->dbError('Can not use Database : ' . mysql_error());
        }
    }