I have used blender for years now, and never seen this happen. It's kinda hard to explain, but I can't directly edit a mesh, because there is another mesh around the object, like a cage. Please see the picture and let me know if you know what is happening. I just want to edit the mesh.
thanks in advance.
It looks to me like you have an un-applied sub-surface (subsurf) modifier assigned to the object. The solid part is the representation of what the object looks like with the subsurf, but since it is not applied, the solid part is not directly editable in edit mode. If you move some of the vertices you can edit, you will find that the solid surface moves, too. An additional clue that this is the case is the normal lines pointing from each face.
When a subsurface modifier is added to a model, the surface "pulls away" from the true vertices of the model. A small protrusion like you have will show an extreme case of this, while on the gentle curved area you can see a small gap between your vertices and the surface of your object.
At the top of all modifier panels you will see buttons that control the display of the changes the modifier makes. The first two apply to the render and object mode viewport display, the last two show the effect in edit mode and the deformed edit mesh. All modifiers have the first two display options while some do not have the third or fourth.
By enabling the last item (the triangle) your vertices will snap to the deformed surface. Disabling the third button (the cube and vertices) will hide the deformed mesh so you can only see the true vertex and face positions.
