This came up on this thread and figured I would post something about it is an easy mistake. The Finesse layout is devided into an Agent and Supervisor section. So adding a tab to the top of the default layout will only add it to the Agent view. You can tell the layouts apart by the following tags:

<layout>
    <role>Agent</role>
    <page>

</layout>

or

<layout>
    <role>Supervisor</role>
    <page>
</layout>

~david