Enterprise Portal: Same webparts are always hidden

Hello,

I try to add same webparts to the enterprise portal of dax 2009.

The Dynamics User Control Webpart "customers" works fine, for example. The customers are displayed in a grid.

But now I want to add the webpart "EPProjTimeSheet". This webpart is always hidden. If I uncheck the checkbox "hidden" in the webpart propertiers, the checkbox is set again after refresh. Other webparts are always hidden, too.

My testuser has delete permissions to all security keys.

Can anyone help me?

Thank you for your help...

Regards,
Frank