tom
archiCAD is not (at present in 8.x) deleting x-ref layers automatically when the x-refs are updated (or even unloaded in their entirety!)
your best bet is to delete the x-refs in question
completely
, then delete all of the layers associated with them and re-import the amended DWGs from scratch.
see the whinge:
http://archicad-talk.graphisoft.com/viewtopic.php?t=173&highlight=layers+xref
and the wish:
http://archicad-talk.graphisoft.com/viewtopic.php?t=126&highlight=layers+xref
better still - call your consultant(?) and talk through with them just which information you would like from them in DWG format. i have found that 10 minutes on the phone every now and then discussing the way each other works, the kind of information we need from each other, and the preferred format/file set-up saves
HOURS of fiddling around with DWGs cleaning them up every time they are updated . . .
~/archiben
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