Attached Raster Image blocks out line/text drawing

This is followup was posted to autodesk.autocad.print-plot and a copy
was sent to the cited author.]

Hello! I've searched many NG's and did not find relative info regarding
the problem I've been having, so a new thread is being started. My
apologies if I've missed previous commentary/help issues.

Hardware/Software Used: Dell 2400 PC 2.8gHz 80MB HD, HP DesignJET 800
(all drivers up-to-date), Windows XP Pro, AutoCAD
2004 w/ SurvCADD XML2 (all up-to-date)

Process: I'm a Surveying Department Manager, so I have background using
CAD to produce surveying/civil plats with image files. My latest
issue involves starting with a drawing generated using field-run
point data, then using XREF to attach (not overlay) an AutoCAD
compatible aerial compilation showing spot elevations and
planimetrics e.g. treelines, streams, roads, etc. and finally
attaching a high-definition 0.25 pixel orthographic aerial
color photograph for background.

Problem: 1> Using normal (not draft or presentation) parameters for the
plotter by setting the output to mono or color and checking
lineweight sizing, and that my lines overwrite in black only and
merge in color, that the plotter settings include "solid color"
and "vivid color" for color plots;

2> making sure that in display view the objects are set to
"solid fill float" and "sent to front"; the raster image is "sent
to back";

3> all layers to be plotted are "on"; and

4> that full preview yields proper output.

I receive a plot showing a great color aerial with only some or
none of the vector lines printing up in the output. I seem to get
better results using black, light blue and green colors than
brown, yellow, red and orange although all the colors are crisp
and clear in the image. I have adjusted all the possible settings
available to me within the drawings and plotting configurations
but still can't achieve the result I want.

It obvious to me that it's probably a setting I'm not familiar
with thats causing the problem. Which one and where its
located within AutoCAD or the plotter is the issue. I've tried the
AutoCAD forum and SurvCADD tech people, but it doesn't seem to be
a software issue. Any assistance anyone can provide will be
greatly appreciated with many thanks.