I am creating a loop bank with Sonar. Sometimes I work with loops and can't get rid of that little tick everytime it loops. Happens when I loop old stuff or constant sounds.
Make sure you trim the clip at the "zero crossing." There's an option in the Snap to Grid dialog to snap to zero crossings. Do this at the front and the back end of the clip. You could also use a fade to fade in or out the part that's popping.