Especially Gnome and KDE is environments which do not benefit from mixing.
Both KDE and Gnome is adding various launchers to the general system autostart found in /etc/xdg/autostart
It is generally a bad idea to mix two different tool sets and in this case two completely different approaches - it usually generates a lot of static noise and probably more issues along the road.
Below from the reference thread is a universal good advise when you want to experiment