ok, this worked in a test I did...

but to simplify my proces, it would help me very much to convert my 4 nurbs surfaces (that I got from extruding a nurbs square following a path, so it's in fact a closed tube) to a editable polygon.

I looked on the internet. It seems the conversion from nurbs to polygon is possible through conversion via SUBd's. So nurbs->subd->polygon.

1) Anyone know how to do this in detail?

2) AND: is it really not possible to choose a grouped set of surfaces in outliner, then choose control vertex mode, so that ALL CV's OF SURFACES are shown at once? Is it really not possible to group nurbs and edit the group at once? maybe through parenting?

Thanks a bunch, I really appreciate the help...

Ken