mysql_fetch_assoc(): supplied argument is not a alid MySQL result resource

[a aoao]

i keep getting the same error no matter what sql query i use. they were all working when i had the file locally hosted on my machine, but since i've started hosting it on a web server it wont work! any ideas!!?

here's my code...

<?
function distance($lat1, $lon1, $lat2, $lon2, $unit) {


$theta = $lon1 - $lon2;
$dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) + cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));
$dist = acos($dist);
$dist = rad2deg($dist);
$miles = $dist * 60 * 1.1515;
$unit = strtoupper($unit);

if ($unit == "K") {
return ($miles * 1.609344);
} else if ($unit == "N") {
return ($miles * 0.8684);
} else {
return $miles;
}

}
$host = 'localhost';
$user = '';
$pass = '';
$dbname = 'rory_racetrack';
echo "Hello world! <br>";
$db = mysql_connect($host, $user, $pass);

if(!$db) {
echo 'Could not connect to mysql';
exit;
if (!mysql_select_db($dbname, $db)) {
echo 'Could not select database';
exit;
}
}


$query = "SELECT * FROM RHUMB";
$query = mysql_query($query);
echo $query;
//echo "<waypoint>";
while ($row=mysql_fetch_assoc($query)){
//echo 'Rhumb Number= '.$row['rhumb'].' latitude= '.$row['latitude'].' longitude= '.$row['longitude'];
$check = $row['rhumb'];
echo "RHUMB:";
echo $check;
echo "<br>";
$latitude = $row['latitude'];
$longitude = $row['longitude'];
$check++;
echo "TWO :";
echo $check;
echo "<br>";
$check2 = $check;
echo "CHECK 2 ";
echo $check2;
echo "<br>";
//echo "<br>";
$query2 = "SELECT rhumb, latitude, longitude FROM RHUMB WHERE RHUMB = " . $check2 . ";";
$query2 = mysql_query($query2);
while ($row=mysql_fetch_assoc($query2)){
//echo 'Rhumb Number= '.$row['rhumb'].' latitude= '.$row['latitude'].' longitude= '.$row['longitude'];
$check2 = $row['rhumb'];
$latitude2 = $row['latitude'];
//echo $latitude2;
echo "<br>";
$longitude2 = $row['longitude'];
}
$disto = distance($latitude , $longitude , $latitude2 , $longitude2 , "n") . " nautical miles<br>";
echo $disto;
$overall = $overall + $disto;
}
echo "<br>";
echo $overall . "Nautical Miles";
/*
echo distance(32.9697, -96.80322, 29.46786, -98.53506, "m") . " miles<br>";
echo distance(32.9697, -96.80322, 29.46786, -98.53506, "k") . " kilometers<br>";
echo distance(32.9697, -96.80322, 29.46786, -98.53506, "n") . " nautical miles<br>";
*/
?>