Biblioscape User Community

These are my first steps in biblioweb (I am now sharing the database with collegues on intranet) and I admit I am a bit confused:
Biblioweb shows the cross-links I had introduced when I did not yet use biblioscape in a multi-user environment, but it seems not to allow me to add any new links neither to already existing references nor to newly written references.
My database is not meanigful without cross-links, what am I doing wrong?

Thanks for suggestions!
Johanna