Ok, tried my simple method of shifting starting point of one track, relative to starting point of all/another track on smaller test files, and it works fine: https://dl.dropboxusercontent.com/u/13327195/delayShift.zip This was since was wondering if couldn't maybe just be a form of system/audacity overload since the two primary files am working on have durations of roundabout 2 hours 49 minutes+ each - but, initial one is roundabout 2 minutes longer than secondary track - was also something was wondering about. Anyway, the zip file above contains the test audacity project, along with two small test files I recorded using my microphone earlier, just for testing purposes, but, if you open the audacity project, you'll see that it worked perfectly when just told it to start selection at a specific point, told it to align cursor with selection start, turned off selection on first/primary track, turned it on for second track, and told audacity to align track with selection start. Thus, am, again, wondering, is it that my issue when working with actual data/files could have something to do with the size/length of the other two files..? Will also try out that timeShifter effect itself, but, would still like to know why one specific bit of data is affecting/changing the way audacity is performing/carrying out a task..? Also specifically tried first converting the original video clip into MP3 before importing it into audacity in case audacity's own import part of process could be affecting overall process, but anyway. Ideas? Stay well Jacob Kruger Blind Biker Skype: BlindZA '...fate had broken his body, but not his spirit...'