Fejl i DB ?

Warning: mysql_fetch_row(): supplied argument is not a valid MySQL result resource in /net/users/a50/160/xupdk/www/boom/online.php on line 16

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /net/users/a50/160/xupdk/www/boom/online.php on line 22
brugere online

Det gir den af fejl.. Hvad fanden er der galt?
www.xup.dk/boom/online.php - det er siden marker siden så ser i fejlen..

Online.php kode:

<?php
print '<font face="helvetica" size="1" color="#FFFFFF">';

$mysql_host = "mysql.xup.dk";
$mysql_user = "xupdk";
$mysql_password = "KODE";
$ip = $REMOTE_ADDR;


mysql_connect($mysql_host,$mysql_user,$mysql_password);
mysql_select_db("systems");
$time = explode(" ",microtime());
$array1 = $time[0];
$array2 = $time[1];

    $r = mysql_fetch_row( mysql_query("SELECT * FROM online_users WHERE ip like '$ip'"));
    if ($r == (false))  {
    mysql_query("INSERT INTO online_users (id,ip,name,date) values ('','$ip','','$array2')");
    }
mysql_query("DELETE FROM online_users where date < $array2 - 400");
$res = mysql_query("SELECT * FROM online_users");
$tal = mysql_num_rows($res);
if ($tal == "1") {
print "1 bruger online ";
}
else {
print $tal;
print " brugere online";
}

?>

Database dump:

CREATE TABLE online_users (
  id int(11) NOT NULL auto_increment,
  ip tinytext NOT NULL,
  name tinytext NOT NULL,
  date date NOT NULL,
  PRIMARY KEY  (id)
) TYPE=MyISAM;

Jeg kan ikke se fejlen, please hjælp!