[Lester Wilson]

Any help would be great! Thanks in advance.
(bits in red changed to protect the innocent)

ERROR MESSAGE -
Could not authenticate you. /statuses/update.xml Unauthorized on line 229 in /var/www/vhosts/mydomain.co.uk/httpdocs/twitter.php
#0 /var/www/vhosts/mydomain.co.uk/httpdocs/twitter.php(648): Twitter->doCall('statuses/update...', Array, true)
#1 /var/www/vhosts/mydomain.co.uk/httpdocs/newthread.php(276) : eval()'d code(23): Twitter->updateStatus('Test from Mark ...')
#2 /var/www/vhosts/mydomain.co.uk/httpdocs/newthread.php(276): eval()
#3 {main}



MY PHP SCRIPT

// If you are having trouble getting bitly URL shortening to work... disable it!
$useBitly = true;

if (!in_array($foruminfo[forumid], $excludedForums)) {
$shortUrl = 'http://www.myDomain.co.uk/showthread.php?t='.$newpost[threadid];

if ($useBitly) {
// http://classes.verkoyen.eu/bitly
require_once 'bitly.php';
$bitly = new Bitly('accountName', 'R_70765765765765765765');
$shortUrl = $bitly->shorten($shortUrl);
}

$tweet = '';
if (isset($newpost['prefixid']) && $newpost['prefixid'] != '') {
$tweet = $vbphrase['prefix_'.$newpost['prefixid'].'_title_plain'].' ';
}
$tweet .= $newpost['title'].' '.$shortUrl;

// http://classes.verkoyen.eu/twitter/
require_once 'twitter.php';
$twitter = new Twitter('accountName','234kjh234k2j3h4');
$twitter->updateStatus($tweet);
}