MySQL error

Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource in /home/....public_html/subdomains/....../sites/all/modules/fb/facebook-platform/footprints/lib.php on line 13

While this is a great module and has great potential I am trying to figure out and make an application. After having some trouble I tried to set up the included footprints example. I keep getting sql errors. I have re read everything several times. Downloaded the latest versions and double checked the code.

The above code points to

function get_prints($user) {
  $conn = get_db_conn();
  $res = mysql_query('SELECT `from`, `to`, `time` FROM footprints WHERE `to`=' . $user . ' ORDER BY `time` DESC', $conn);
  $prints = array();
  while ($row = mysql_fetch_assoc($res)) {
    $prints[] = $row;
  }

with line 13 being while ($row = mysql_fetch_assoc($res)) {
Can anyone help?