I've been a Cakewalk user since about version 9 ( pre Sonar).  I used to use the "extract  timing" function to turn a kick or snare track into a midi track  to trigger a drum sample.  I now have X3, and have repeatedly read the instructions on how to use the "audio transients" view and AUDIOSNAP to do the same thing.  I have a peculiar problem.
 
Assume I have separate kick and snare audio tracks, and want to extract the timing of these tracks as a midi note to trigger addictive drums.  The process in the manual works well ON THE FIRST TRACK THAT I TRY TO EXTRACT TIMING FROM. However, once I have done this, it will not work on any additional track.  If I've extracted the kick first, when I go to the transient view on the snare track, instead of showing the transients, it marks a small diamond with no line on EVERY QUARTER NOTE, even before the snare starts playing.  Adjusting the threshold in AUDIOSNAP does not help. Nor does making sure AUDIOSNAP is turned off on the previous track.
 
 If I go ahead and extract the midi data, one of two things happens: if the extraction is set to a fixed velocity, I get an audiable snare beat on every quarter note on the midi track.  IF the velocity is set to track the volume of the audio signal, I get a note on each beat, but most of them have a velocity of 0!
 
 Is this a bug, or am I doing something wrong!

martinh
it marks a small diamond with no line on EVERY QUARTER NOTE, even before the snare starts playing.

Those are "User" markers that SONAR inserts to keep track of timing in parts of an audio clip where there are no audio transients to reference. Sometimes it fouls up and inserts them where there are other transients but that's another issue. In any case, you can either right-click, Select Markers > User and delete them (keybinding "AudioSnap Delete Inserted Marker" can help here since it only deletes one at a time) or just disable them so they're not included in Copy As MIDI.

I highly recommend checking out Melodyne's audio-to-MIDI functionality.

You may want to try seeing what Melodyne will do with this. You say you have a separate snare and kick track? You should be able to just have Melodyne detect those hits and turn them into MIDI. Whammo blammo you can make the resulting MIDI track trigger something.
 
Now if you are actually trying to extract a tempo so the project reflects those tempo changes... that feature is weird and usually requires a bunch of manual fiddling. In which case you can go to VeryFastBikerBoy's youtube page and watch the videos on tempo extraction. Be sure to watch both videos.
 
1:   http://www.youtube.com/watch?v=weIZy_ibH5c&index=3&list=PL6C8A51A85BDA4609
 
2:   http://www.youtube.com/watch?v=7VR7WkHywTo&list=PL6C8A51A85BDA4609
 
 

Thanks everybody - I hadn't though of using Melodyne because I just got X3.  After a lot of messing around last night, I did find a solution.  the problem appear to be that the first time I use Audiosnap it sets the tempo for every clip as the tempo of the first clip I did a midi extraction from.   This would not be a problem except:
 
1. Using the "extract every trigger at same velocity " setting it extracts every little tempo diamond  as a midi note, e.g. you  get a midi kick track that has straight 4 beat kick superimposed over the actual kick drum; and
 
[2] it apparently it won't  detect transients that are too far away from the tempo is has interposed on the track.
 
 The solution is that I have to reset the tempo map each time I try and extract from a different audio track in the same project.  Then the second, third tracks etc work  just like thew first one did.

Looks like you already figured out what I should have mentioned that the issue with superfluous User markers is exacerbated by having the wrong clip map tempo set.
 
Regarding Melodyne, I'll just say that in my (admittedly limited) experimentation AudioSnap still does a better job of converting to MIDI with the most accurate timing in cases where pitch isn't relevant.