Fixed in NWC 2.5:
!NoteWorthyComposerClip(2.5,Single)
|Chord|Dur:8th,Triplet=First|Pos:-4,3|Opts:Stem=Down,Beam=First
|Clef|Type:Bass
|Chord|Dur:8th,Triplet|Pos:1,4,8|Opts:Stem=Down,Beam
|Chord|Dur:8th,Triplet=End|Pos:1,4,8|Opts:Stem=Down,Beam=End
!NoteWorthyComposerClip-End