Hi Rick,
I do see the effect Lawrie describes now, with the grace note in bar 3 crowding the bar line in front of it, in print preview. I didn't see it until I changed printer settings to 300 dpi, but now that I've done that, and switched back, the poor placement continues.
I still don't see a difference between the length of measures 2 and 3. On my flat screen, highly magnified, in preview they are both 4 centimetres. Bars 1, 4 and 5 are about 3.8 cms. The difference would only be attributable to the grace note widths, I think.
Anyway, it doesn't matter if I can see the problem or not. You're encountering it, and it may be a bug.
What is it you were trying to do? I can see trying to use grace notes for cues by anchoring them to hidden rests (I tried that a few days ago, unsuccessfully). You can do cues by using grace notes anchored to real notes on a second staff, and making the real note properties visible, muted, blank notehead, stem length zero.
Try this
Staff 1
!NoteWorthyComposerClip(2.0,Single)
|Rest|Dur:Whole|Opts:VertOffset=-2
|Bar
|Rest|Dur:Half|Opts:VertOffset=-2
|Rest|Dur:4th|Opts:VertOffset=-2
|Note|Dur:4th|Pos:-2
|Bar
|Note|Dur:Half,Dotted|Pos:-1
|Note|Dur:4th|Pos:1
|Bar
|Note|Dur:4th,Dotted|Pos:1
|Note|Dur:8th|Pos:-1^
|Note|Dur:Half|Pos:-1
!NoteWorthyComposerClip-End
Staff 2
!NoteWorthyComposerClip(2.0,Single)
|Note|Dur:4th,Grace|Pos:5
|Note|Dur:4th,Slur|Pos:5z|Opts:StemLength=0,NoLegerLines,Muted|Visibility:Always
|Note|Dur:4th,Grace|Pos:6|Visibility:Always
|Note|Dur:4th,Slur|Pos:5z|Opts:StemLength=0,NoLegerLines|Visibility:Always
|Note|Dur:4th,Grace|Pos:7|Visibility:Always
|Note|Dur:4th,Slur|Pos:5z|Opts:StemLength=0,NoLegerLines,Muted|Visibility:Always
|Note|Dur:8th,Grace|Pos:b7|Opts:Stem=Up,Beam=First|Visibility:Always
|Note|Dur:8th,Grace|Pos:6|Opts:Stem=Up,Beam=End|Visibility:Always
|Note|Dur:4th,Slur|Pos:5z|Opts:StemLength=0,NoLegerLines,Muted|Visibility:Always
|Bar|Visibility:Always
|Note|Dur:8th,Grace|Pos:b7|Opts:Stem=Up,Beam=First|Visibility:Always
|Note|Dur:8th,Grace|Pos:6|Opts:Stem=Up,Beam=End|Visibility:Always
|Note|Dur:4th,Slur|Pos:5z|Opts:StemLength=0,NoLegerLines,Muted|Visibility:Always
|Note|Dur:4th,Grace|Pos:5|Visibility:Always
|Note|Dur:4th,Slur|Pos:5z|Opts:StemLength=0,NoLegerLines,Muted|Visibility:Always
|Note|Dur:4th,Grace|Pos:6|Visibility:Always
|Note|Dur:4th,Slur|Pos:5z|Opts:StemLength=0,NoLegerLines,Muted|Visibility:Always
|Rest|Dur:4th|Visibility:Never
|Bar
|Rest|Dur:Whole
|Bar
|Rest|Dur:Whole
!NoteWorthyComposerClip-End
Layer them. Playback seems wonky, but this is for printing, no?