After I have deleted layers from a base file (xref) and purged the file, they still display in the Layers Properites Manager listing in the file (sheet file) it is xrefed to.
How can I "purge" these non-existent layers?

Have you tried purging that file as well?if that doesn't do it, you may have to detach, set visretain to 0, reattach.

Thanks for the reply, CarlB
Yes, I purged both the xref and the sheet file.
 
I may be wrong, but it seems like ACAD used to update layer lists in Layer Properties Manager for xrefs.
 
I have detached/reattached xrefs, but that means everything you have done to the xref attachment must be redone. I was hoping to avoid the re-do.
 
I thought there might be some setting I'm not aware of.

Have you tried closing then opening the "sheet file"?  According to the link that should do it, but a lisp solution is also posted that should purge without that step.http://discussion.autodesk.com/forums/thread.jspa?threadID=413643

I think some others layers hiding use command "layon". bec. u cannot deleted layers if it use. so try layon to unhide others object.

DOH!
I followed the link, but found it unnecessary. During a work session, I keep files I am working on open until they are complete. Of course those purged xref layers go away when you close/reopen the file.

Thanks for all the replies.

Try this link to Lynn Allen's video tip site on CADalyst.comhttp://video.cadalyst.com/The look for "Delete Stubborn Layers in AutoCAD"or use "laydel" command.
Breeze1042009-12-29 15:51:51