Sometimes when using Haku Mirrors, the following can happen:

-You hit yourself (Really really sucks)
-If you macro a different jutsu like suiton (i can't remember name) Waterball technique, Ull, cancle your mirrors but hit 4 times with the technique which sometimes does massivly more damage. (immagine using that earth jutsu doryo Dango with it) Although this may be benificial, i still feal this should be fixed o-o.
-The ability to get yourself stuck in water or a wall(outer wall of villages)