What induction unit are you using? The cheap ones don't manage heat very well. They're also not good at seasoning cast iron or carbon steel, since these don't conduct heat well and form a concentrated hot spot over the induction coil (which is much smaller than most pans).
Edit: I saw the brand you're using, and would expect it to perform well. My comments mostly apply to portable induction burners. I'd be interested in hearing more from this those with full cooktops.