Background Hatch not Covering Ref Attachment Linework

I am trying to cover up some lines by keeping them behind a dense hatch colored 255. I cannot trim/remove the lines from this area. I have used Edit>Bring to Front to make sure my hatch is in front. It looks OK in the editing space, but plots with the reference files lines in front to the hatch.

I created a level with a particular name, put the hatch on it, edited the pen table to recognize this level and, using plot priority, plot in front of the level that the lines are on: hatch priority 50, lines: priority 45. This worked for about one day, but the next it went back to plotting the lines in front.

is there anything I can do to get the lines to be consistently covered by the hatch when plotted?

thanks,

david

V8i SS3