It is difficult to position items in the timeline at a specific frame. If you position the playhead where to want it (say, a sound clip) and then click on the clip, the playhead moves to the start of the clip where it currently is.
Nothing wrong with that.
But then you have to move the clip to what looks to be the correct frame.
Other timeline driven software (anything Adobe) allows you to position the playhead, add a marker, and then snap the clip to that marker.