I do not understand what " Align View to Selected" does.

I select a face from a mesh and press «shift numpad 7», the 3D view is supposed to oppose the normal of the face, and it does but I don’t understand why it also rotates.

I’ve got another problem. Now, for some bizarre reason, I press «numpad 1» and the text in the top left of the viewport changes to «Front Persp» but the view is slightly tilted to the left and transposed to the right.

Blender 3D 2.69 on Windows Vista 32bits

You’re viewing it in perspective so Z doesn’t actually point at you.

Face normals get calculated from vertex normals and if the polygon is not symmetrical, axes don’t seem to align to it even when it does. Quadrilaterals and n-gons can also be non-planar in which case the view would align to the averaged plane but the rotation wouldn’t again seem to align to anything.