Hmmm strange..
I also got a 7-4 an d the setup was pretty easy in terms of PowerLink & speakers.
If you sit behind the TV, on the right hand side in the middle you find the speaker section.
First connector is the center, second connector the sub, all other connections are free.
Plug your speakers in and go to the software menu and select the attached models, you should hear a noise signal from the speaker you just highlighted/selected, so its easy to assign the slot to the speaker
After that, you select the setup in a different menu as you go over each virtual connector and assign the position (rear, front left, surround etc)
Thats about it....
Another thing, forget the "surround" speakers, if you have a classical 5.1 (front/rear/center/sub) setup, you assign the rear speakers as "rear left / right" not surround!
I cannot tell you any specifics but it works like that with my setup (BL7-4 as center / Beolab 5 as front left/right and Beolab 8000 as rear left/right)
Rgds
Stephan