1. Bring a MP3 to the session.
2. Adjust the warping on the clip.
3. Make copies of the clip to define cue points, loops etc.
4. Drag the edited clips to the directory where the original MP3 is, creating a project directory containing the clips/live set.
5. Drag a clip or the whole set back to a new session and all the warp/cue/loop info is lost.
I can't guarantee you'll be able to reproduce this behavior, but I have a set that is failing to reload the infos. This happened more than once, but several other sets made in the exact same way work perfectly.
I'm sending a copy of this to [email protected] along with the failed set.
Update: It seems I'm not the only one with this problem (and maybe the bug is quite old):
http://www.ableton.com/forum/viewtopic.php?t=54101