Need to reduce latency on drum pad

I just got an Akai MPC218 and am finding a big lag between hitting a pad and the sound going off in Cubase Pro 11. I use a Focusrite Scarlett 2i2 for the audio interface. I have played with setting the buffer size to as low as 64 but the lag is still great enough to make the drum pad unusable. Normally I record audio like guitar and vocals with a 128 buffer and 44k Hz and have never found a problem. I bought it so that there would be better response to tapping than on a regular keyboard.