Outlook 2010: Missing ribbons

Hi

A new installation of Office 2010 x64 does not show not all ribbons only in Outlook
as I write an email (3 ribbons are not present). All other Outlook-Windows like
tasks and so on are ok.
Neither adapting the ribbons nor resetting ribbons to defaults make them
visible again.
Unchecking and rechecking a invisible ribbon like the ribbon "options" does
not help either.


Thanks for your help.

Patrick