Hi Bernhard,
I had the same requirement than you when I impemented PPM. We created the item and cProjects and the name of the cProjects was only updated in the logon languages the other languages remains with the template name.
I rised to SAP this issue but I didn't obtain the solution, then finally we decided to let the users logon only in EN (PPM) and they can use other languages in other SAP applications.
Regards,
Clara