I'm following the method described in this link: http://www.youtube.com/watch?v=WHUuWZ4xE7w&feature=channel to quantize some multitracked drums...overall this guy's videos are pretty clear, but where I run into a problem with this one is when it's time to cut into the 1/4 note slices using option/scissor tool..the beat mapping "track" places the 1/4 note grid divisions right on the transients, but the multiple 1/4 note slices I get after using option/scissors are not on the transients. Consequently, the resulting regions don't have the drums hits at the start of each region as they should. I've cut audio regions into multiple exact 1/4 notes, 1/8th notes, etc. many times slices this way with no problem, so I'm not sure what I'm doing wrong this time but it seems like it has something to do with using Beat Mapping. As described in the video, I make a MIDI track from the most important drum tracks (kick and snare, in this case) and use Beats from Region to generate the tempo map. Thre are some other part of the video that I'm not clear on, like where he describes choosing an alternative tempo to get back to the original tempo. Is there a better description of this method of drum quantization available somewhere? It seems like if it worked right, it would be much faster than the "tab to transient" method, which is really time-consuming.