This happened to me on both of my C3D 2012 installs. This can be fixed by manually loading the map menus. Enter the CUI (Command: CUI) and scroll down to "Partial Customization Files" on the left side of the window. Right click on that and then "Load partial customization file." This will open up a window with all the cuix files. I loaded "Map3DGeospatial.cuix" and "Map3DDrawings.cuix" and that loaded all the 2011 Toolbased and Taskbased geospatial ribbons.