simple trick: there is a filter, that will only show service items, that are published to the users. So if you choose any user, that has no published items, the service will disappear.
There are two ways to cope with that:
- Add the attribute "Publish to all" to your service window and set the boolean to true in every service you have.
- If you do not want all users to see the services, you have to publish them. Use the Administration - Service Catalogue for publishing.
After that, rightclick on the publishing tab (3) and select "Rebuild Catalog Search Index". Then you should be able to select a user as well as a service.