Hi Sashko,
you need to be on certain SP level(l'm on 7.4 SP11,a nd I've this option) to be able to create annotation projects of type 3 -Annotation model for referenced service. This type of project can be used however for projects created with type 2 - Service with vocalbulary-based annotations only. You can check the level on your systemis,after logon. In the top cascade menu: System->Status->Component version. I my case the above will never work, I need to copy my project of type 1 to 2.
Attila