I've followed Gert's instructions (http://k2underground.com/forums/thread/20260.aspx) and I've added another domain to the default security label (K2). Yet, when I give Management permissions to a user in this domain, they still don't have the "Management Console" tab when they open the workspace.
Moreover, if I simply give "Start process" right to a user in this additional domain, it doesn't work, no process instance is created (I don't have any error as this is a process that should start on Sharepoint DocLib item upload).
What the definitive procedure to work with users in different domains?