Oldjohn

When I enable transitions in the editor they appear in the timeline, can do a frame by frame and they seem OK. When I enable preview it freezes/gets jerky and generally seem confused as to what to display. Doing a movie build generates a movie with the transitions present. Using 4.0 free version and trrying to decide whether to upgarde or choose a different video editor. Using an older laptop and attempting to avoid an editor that requires massive RAM and multi-core CPU