in_array(): Wrong datatype for second argument

[SmEdD]

Warning: in_array(): Wrong datatype for second argument on line 123

PHP Code:

if ($bbuserinfo['userid']) {
    $datecut = $bbuserinfo['lastvisit'];
} else {
    $datecut = TIMENOW - (24 * 60 * 60 * 1);
}

$countnew = $DB_site->query("
        ## GET NEW POSTS / THREADS ##
        SELECT post.postid, post.threadid
        FROM " . TABLE_PREFIX . "post AS post
        WHERE dateline >= $datecut
        AND visible = '1'");

while($getnew = $DB_site->fetch_array($countnew)) {
    $new['posts']++;
    if (!in_array($getnew['threadid'], $threadids)) {
        $new['threads']++;
        $threadids[] = $getnew['threadid'];
    }
} 


Line 123 is

PHP Code:

if (!in_array($getnew['threadid'], $threadids)) {