Currently (build 266) there is a minor but annoying flaw inside ShaderProgram's constructor: After compiling and linking the shader the following code is executed:
if (log!=null && log.length()!=0) Log.warn("GLSL Info: "+log);
However, some drivers do return a non-empty log in case of succesfull compilation (e.g. "Fragment shader was successfully compiled to run on hardware."). This leads to a message box basically telling "ERROR! Everything went fine!".