Problem with RibbonTab

[John]

Hi,

I have developed an Office Addin with VSTO2005. So far, everything is fine.
I have a new RibbonTab which is inserted after the "Developer Tools"-Tab.
But now I have a problem, when I select a table in a document. Before I have
activated the Addin, I got a new RibbonTab ("Table Tools") when I have
selected a table. But now there is nothing!!!
Does anybody know, why the "Table Tools"-Tab is not shown any more?

Regards,
John