I’m using Blender 2.55. Create a cube or start a new scene. Go to Display/Toggle Quad View. Select cube and go to edit mode. Go to vertex mode. Try to box-select vertex on one side of the cube. You will see two selected vertex , not four selected vertex. Is it possible to box-select four vertex?
When in edit mode, a new set of icons appears in the 3D view. Along the bottom, there is a square with 4 white dots, and another faded square behind it. Toggling this icon will allow your selections, box selection included, to extend beyond what is visible in the viewport. So you can select vertices, faces and edges that are hidden behind your initial selection.