Normal map issues, I think the tangents are wrong

I have a model made in blender, which I've exported as a collada file. When loading it in my game engine, I get the result as shown in picture A. The code used to calculate the tangents are shown in picture B. If I set the tangents to something like (1,1,1) I get a much more smooth result but it gets very blocky in the places where there's supposed to be fine details (on high poly models). If I export the model to obj-format and load it in my engine through another pipeline, which uses the …