There's no '&' in the PHP code of our online_location_unknown plugin. It's probably caused by another mod.
Code:
<plugin active="1">
<title>downloads_location_unknown</title>
<hookname>online_location_unknown</hookname>
<phpcode><![CDATA[if ($userinfo['activity'] == 'downloads')
{
$userinfo['where'] = '<a href="downloads.php?'.$vbulletin->session->vars[sessionurl].'">'.$vbulletin->options[bbtitle].' Downloading Files</a>';
$userinfo['action'] = 'downloads';
$handled = true;
}]]></phpcode>
</plugin>
If DownloadsII would be the only mod you used with such a online_location_unknown plugin, then this line should be wrong:
PHP Code:
$userinfo['action'] = 'downloads';
Which seems ok to me, no '&'