Android : OpenGL problems on Android (Galaxy S3) - not drawing polygons for official tutorial

I started using OpenGL 2.0 by following the official Android tutorial: http://developer.android.com/training/graphics/opengl/index.html . Basically, I could do mostly copy and paste for my game which uses just a few colored polygons: https://play.google.com/store/apps/details?id=de.timedout.mosaic.app

I tested the game on several devices and it worked. However, I also just tested it on a Samsung Galaxy S3 (Android 4.1.2) and there it only shows the background and no polygons. However, I do not get any error message. Ok, so I went back to the official tutorial and tested the code for both OpenGL 1.0 and OpenGL 2.0 on the Galaxy S3 which leads to the same result: it draws the background but no polygons! At the same time other OpenGL benchmarks from the market run well on the device. Does that mean that the official code from the tutorial does have some flaw? - I am a total OpenGL beginner, does someone have a hint for me with this problem?