Obviously, "rpool" was not what I thought it was... So, no solution so far. At least I have two working installations now (linux and Solaris) - all I have to do is change boot priority every time ...:)
I am confident that I will find a good solution soon. I think that all I have to do is update the "grub.cfg" file, but it has to be done correctly. -- This message posted from opensolaris.org