Blender Environment Map - Beginner tutorial required

Hi,
I am new to use blender. I am using Blender 2.58. I am trying to set a environment map for an object.

  1. I have a default blender scene (Cube, Light and a camera)
  2. The Cube is having a material assigned and that material is having a texture(but it is none)
  3. I changed the texture type to Environment map
  4. I changed Environment map type to Image File and loaded the image from the following link,
    http://en.wikibooks.org/wiki/Blender_3D:_Noob_to_Pro/Build_a_skybox
  5. Then i changed the Mapping Coordinates setting to Reflection

I am confused with the rendered output …
Rendered output is not having the reflection continuity on the adjacent faces when mapping to a Cube.

The same texture if i map to Sphere object, the textures looking like continuous.

Is there any dependency between the Texture size and object size…
I tried mapping texture of 300200 to a cube with dimension of 100100*100…

My doubt is when i set the texture coordinates setting to “Generated”, that output and reflection output shouldn’t be the same?