Hi David,
it seems to me that using RenderingHint in AbstractCategoryItemRenderer.drawRangeLine() causes my problem.
A RangeMarker at y=0.0 and BasicStroke(0.5) and a GridLine at y=0.0 and BasicStroke(0.5) do not hide each other in all zoom status.
So if zoom scrolling, sometimes both appear.
Thats a difficult to handle aspect, as all coodinates in double are identcal.
I would suggest that optimization should be centralized.
Am i right. Overriding in all my renderers and comment out the usage of RenderingHint solves it.
But i would prefer a kind of bug fix.
best regards
markus