I am running Ubuntu 12.04LTS 64bit. I prefer KDE so I installed it a few weeks ago but several times I have woken my laptop to find it is back in Unity. Sometimes it is a mixture of the two as odd as that may sound. I mean, I have had the KDE 4 task bar at the bottom with the menu as normal but with the Unity wallpaper and icons.
Although I have played with Linux on and off for years and am still very much a novice.
Any help greatly appreciated.