My DSTwo works fine on 4.3.0 and 4.5.0 3DS's. You just have to run the GW exploit after every time you have used the DSTwo card.
Actually if you do use your DSTwo card then just run the browser exploit when you have finished, no need to run the blue card exploit anymore to activate NDS Profile. I think the new browser method is way better, I'm lovin it!
Edit: the DSTwo Supercard is one hell of a card, a fantastic purchase in my opinion but my only niggle about it is the fact that the top screen with a 3DSXL does not use the whole screen and it only runs on a smaller ratio, if that was fixed I would be in DSTwo Supercard heaven but that does bug me out a tad playing the likes of SM64DS! Its a shame know one developed a quick patch for that problem to fix it.