when i chop up a loop/sample then sometimes i want to change it to a other loop/sample, i use the sample editor and drop the new sound into it. mostly works fine. but sometimes i have to chop it up again in the column editor. why is this ? does it have anything to do with any loop points in the wav file that i use ?
damn this proggy is highly addictive… 
The sample will be automatically divided into 256 even pieces for the 09xx command, when changing the sample it might be due to different sample length / tempo or a not well cutted loop, that the internal markers fall on different positions. Just a guess though.
it’s because your offset instructions go to a specified interval relative to the length of the sample, and not ‘the snare sound’ or ‘the hat’