I have a lot of non overlapping audio events and if I select events to parts in CB 5 they land on the same lane in the audio part editor.
Were all these events on the same lane in the audio track before you put them inside the audio Part?
(just to check… dissolve the audio Part, and switch on the Lanes button for that track, see where the actual events end up). If they are on the same lane in the audio track, they should be on the same lane inside the Audio Part Editor.