Characteristic not visible in tree?

Hi,

why is it that some times infoobjects are not visible in the tree under the InfoObjects tree in the modeling tab-strib?

None of the characteristics on this system are available, but I can find the infoobjects from transaction RSD1?

I have installed cubes with all before in dataflow and thereby also the infoobjects and the infoareas from business content, but they don't show up in the tree when I switch to modeling.

I can create an InfoObjectCatalog and add the infoobjects, but I would have expected the infoobjects to be available without this manual step.

Have I overlooked something obvious?

Regards,

Christian