just looked it up. Never realised that TANGENT/BINORMAL are not for output - a dev learns something new everyday 
There were some other hickups involved, which may or may not help anyone who struggles with the GLSL compilation:
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if you define default values in HLSL, those will not be taken over to GLSL - always assign every (global) parameter over the effect class (took me a while to find out why some lighting is weird)
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a wierd thing was, that I had to normalize to normals after multiplying with WorldInverseTranspose in GLSL but not in HLSL. took me several hours to find out why tthere were issues with lighting