You can try that too (copying session files). Or you can try to take the session file out of the gnome package. The package manager displays the list of files in a a package you can even search for a file in the package manager. If you've found your session file, download that package manually, do not install it, and simply open it with mc (midnight commander) and copy your session file wherever you want.
Or you can wait until a Gnome user here copies his\her session file here.
And never-ever login as root.