Hi,
If you view the source of the rendered page do you see the script for cluetip?
<script src="/ClientScript/jqmojo/jquery.cluetip.js" type="text/javascript"></script>
If you upgraded from an older version of mojoPortal, you may need to add
<portal:ScriptLoader id="ScriptLoader1" runat="server" />
into the <head></head> section in the layout.master file of your skins.
Hope it helps,
Joe