I installed Sabayon 8 KDE version. Then I installed GNOME desktop with equo install @gnome. In KDE, I have Restore previous session turned on in System Settings > Startup and Shutdown > Session Managament. Everytime I logged into KDE, a Nautilus window would open with the home folder, even after starting with a fresh KDE session. Also, I noticed that GNOME desktop was running under Plasma Desktop. The problem is not apparent in KDE unless you open System Monitor and see nautilus running when it shouldn't be or turn on session management. I figured out that the following autostart script is causing this.
This is easily fixed by adding the following entry to that file:
I don't know if there are other GNOME autostart scripts that need to be adjusted as well. This fix should be added to future releases and perhaps the Sabayon team should check for any other autostart scripts that need to be adjusted in the same way.