carbon copy in nested block not working

    Recently I updated my config to save copies of one list's messages in two
separate folders, for reading and for archiving:

:0 E
* ^Sender:.*multimedia
{
  :0: c
  mm.ml.new

  # This doesn't work for some reason
  :0:
  mm.ml.archive
}


Seems straightforward enough, but messages aren't saved in mm.ml.archive.
I've tried several dozen variations with no success.  Any thoughts on why
this doesn't work?

Randall Hopper