Grr! I have exactly the same problem. I got Gofriller cello and Strad in the Go-round at Xmas time. I have installed them, but they don't show up in Finale 2008a... So, effectively, they are useless to me, except for real-time playing through the stand-alone Kontakt2 player.
How can I get them to work correctly in Finale 2008a??
I've also heard other people have problems with the cello being an octave too low... If I find that occurs, how to get a fix for it???