I just updated to AutoCAD 2007.
Historically, we plot black/white/halftone and set our plot driver to "lines overwrite" instead of "lines merge" to avoid having our 30% greyscale solid hatch shades, lwpolylines and other simlarly shaded items from writng over the top of outlines and other elements. This avoids having to worry about setting the draw order all the time, and besides, previous (ver 2000) did not respect the draworder of xrefs and nested xrefs. "Lines merge" has certain advantages though that I would like to take advantage of, such as the use of wipeouts and other masking techniques.
I thought 2007 would solve the xref problem but that does not seem to be the case. My shaded objects still randomly pick their draw order when in the top level drawing containing xrefs, even though the draworder is correct in the outside drawing. Setting HPDRAWORDER to 1 or 3 does before doing the hatches does not solve the problem. Using DRAWORDER command does not solve the problem. The objects will be correct in the drawing where I use those commands to create and order the objects, but the order is still not respected when xrefed into another drawing.
Additionally, DWF publishing is also causing a related problem. Using HP1050C, driver, or a kip plotter driver (both set to "lines overwrite"), my DWF's still randomly place my halftone solids over the top of other solid objects. I am at a complete loss.
Any suggestions besides call Autodesk and beg them to fix it.