OpenGL ES 2.0 artifacts/dithering in fbo on Mali-400
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When rendering to a frame buffer object in gles 2.0 I have some strange artifacts on the Mali-400 gpu. Problem is that some pixels have different colors than others even if I fill the whole screen with the same color. But it works fine on a Tegra2 gpu. Does the Mali use any texture compression by default? My fbo uses GL_RGBA as internal format. 
Thanks in advance! 