Aha, I found out why it wasn't working. For some reason the 'gsbos' template wasn't adding itself to the xml file. I'll release an update in a few minutes.
For now, you may create a custom template called 'gsbos' and add the following to it. Be sure to delete this before installing the new version when it becomes available.
HTML Code:
<table class="tborder" cellpadding="$stylevar[cellpadding]" cellspacing="$stylevar[cellspacing]" border="0" width="100%" align="center">
<thead>
<tr>
<td class="tcat" align="center" colspan="3">
<a style="float:$stylevar[right]" href="#top" onclick="return toggle_collapse('gsbos')"><img id="collapseimg_gsbos" src="$stylevar[imgdir_button]/collapse_tcat$vbcollapse[collapseimg_gsbos].gif" alt="" border="0" /></a>
GSBOS
</td>
</tr>
</thead>
<tbody id="collapseobj_gsbos" style="$vbcollapse[collapseobj_gsbos]">
<tr>
<td align="left" width="100%" style="background-color:{$vbulletin->options[gsbos_background]};color:{$vbulletin->options[gsbos_foreground]};padding:0px;">
<div id="gsbosshow" class="smallfont" style="overflow:auto;width:100%;height:{$vbulletin->options[gsbos_height]}px;background-color:{$vbulletin->options[gsbos_background]};color:{$vbulletin->options[gsbos_foreground]};">
#GSBOS> Loading...
</div>
<div id="gsbosinput" class="smallfont" style="width:100%;background-color:{$vbulletin->options[gsbos_background]};color:{$vbulletin->options[gsbos_foreground]};">
<form action="gsbos.php" name="gsbosform" onsubmit="gsbos.sendInput(); return false;">
><input type="text" name="message" id="gsbos_message" class="smallfont" style="width:95%;background-color:{$vbulletin->options[gsbos_background]};color:{$vbulletin->options[gsbos_foreground]};border:none;" />
</form>
</div>
</td>
</tr>
</tbody>
</table>
<br />
<script type="text/javascript" src="clientscript/gsbos.js"></script>
<script type="text/javascript">
<!--
gsbos = new gsbosEngine();
gsbos.init(<if condition="$vbulletin->options[gsbos_typo_enable]">{$vbulletin->options[gsbos_typo_rate]}<else />0</if>, {$vbulletin->options[gsbos_speed_message]}, {$vbulletin->options[gsbos_refresh_interval]} * 1000);
-->
</script>
Please remove the script that germinus posted too, as they will conflict.