First of all, are you using Blender's Internal Renderer or are you using YafRay?
If you're using Internal Render; I'm not entirely sure, but I think that the CVS version of Blender actually uses the HDR data, but 2.41 doesn't. Therefore the CVS version would look more realistic, because it is ACTUALLY using the HDR data and v2.41 is not. Again, I'm not actually certain about this.