Another bug in this release.
!NoteWorthyComposerClip(2.0,Single)
|Chord|Dur:Half,Grace|Pos:0|Opts:Stem=Down|Dur2:Whole,Grace|Pos2:2
|Note|Dur:Half,Grace|Pos:0|Opts:Stem=Down
|Chord|Dur:4th,Grace|Pos:0|Opts:Stem=Down|Dur2:Half,Grace|Pos2:2
|Note|Dur:4th,Grace|Pos:0|Opts:Stem=Down
|Chord|Dur:8th,Grace|Pos:0|Opts:Stem=Down|Dur2:4th,Grace|Pos2:2
|Note|Dur:8th,Grace|Pos:0|Opts:Stem=Down
|Chord|Dur:8th,Grace|Pos:0|Opts:Stem=Down,Beam=First|Dur2:4th,Grace|Pos2:2
|Note|Dur:8th,Grace|Pos:0|Opts:Stem=Down,Beam=End
!NoteWorthyComposerClip-End
Invoking: Tools->Audit Note Stems
on the above clip changes the duration of the Chord in all but the last (beamed) group.
Even worse: Select the entire staff and click the Stem Up button. Durations change and stems disappear.