It may be just me, but since I upgraded to 2.78a I cannot use the 3D cursor when I right click. Is there somewhere I can turn it on ? I can remember first using Blender and cursing the 3D cursor, but now I’m cursing because I don’t seem to be able to use it. LOL
After upgrading to 2.78a you should have been asked if you wanted to import the settings and preferences of the previous Blender version: It sounds like you opted not to…?
By default Blender uses right click to select and left click to position the 3D cursor… Just switch that around in the user preferences.