Old Gnome - New Gnome

It seems that if you have a common home directory that you reuse from fedora version to fedora version, you cannot automatically go into the gnome shell in F15 Alpha gnome 3. I have a home directory that has been around since about Fedora 6. I don't know what all you have to eliminate--I just cleared out all gconf* gnome* gtk* metacity folders and now Fedora 15 RC2 goes into the shell when logging on to the desktop. Before I had to issue a gnome-shell --replace in a terminal. I wonder what other problems reusing was/is causing? -- Regards, OldFart