The OpenGL Samples Pack 4.1.5.1 is a revision which updates the external libraries used, fixes few bugs and add a couple of new samples.
One of the main problems fixed is that a lot of OpenGL 3.3 samples were using some functions that are not OpenGL 3.3 but OpenGL 4.0 or 4.1. I didn't notice any used and as the extension are exposed the functionalities can be used but no extension checking were either done... This is in a way just a change for the sake of pedanticity.
I have also added a really simple sample showing the use of GL_EXT_shader_image_load_store to texture a quad. This is as simple as it can get but AMD drivers doesn't handle it properly. I figured out a way to make it works on AMD but this solution didn't seem to follow the spirit of this extension. It's very possible that this extension specification totally lack of accuracy to be implemented correctly. I personnally had quite some difficulties to figure out how to do right this sample...