Help with Taki on Soul Calibur IV!!

Ok, so, for the record, the combination for Taki's midair grab combo is as follows:

1) Launch them up using A+B.

2) Stalker (A+K)

3) Grab them (A+G)

Now then, I can't perform this combo even in training. If I perform stalker too quickly after that bomb charge, it will cancel it out and Taki simply slices at their face. If I do it to late, the opponent is far too close to the ground for me to grab them. Is there something I'm missing? And tips on the timing? Could it have anything to do with the fact that I have A+K mapped to the R-bumper, and A+G mapped to L-trigger?

Thanks for your time.