I can't Bamboo Rain?

I use it successfully by pressing UP first and then Alt+Ctrl at the same time while holding UP. I noticed that it was really difficult when that backwards status thingy was on during Leviathan, and I had to switch back and forth between UP and DOWN arrow keys (sometimes pressing both at the same time I think) before Bamboo Rain would kick in. Other than that, what I said earlier works for me every time.