[itsm] OTRS::ITSM 1.0.0 RC1 - Ticket <-> Service

Hello, I'm testing OTRS::ITSM right now and just discovered a strange behavior: I set up 3 services and tried to assign them to a test ticket. But for some reason neither in the e-mail ticket form nor in the telephone ticket form a service is selectable - the box just offers " - "... Is this a bug or am I doing something wrong? Thanks for your help, Jens