nnir with maildirs and swish-e

[andy@yovo.org (Andy Jacobson)]

Howdy Folks,

Gnus 5.10.2
Gnu emacs 21.1.1
nnir.el 1.3 from http://quimby.gnus.org (~ 1.80?)
swish-e 2.4.0

    Once upon a time I had nnir working with nnml mail, but now I've
switched to using nnmaildir, and I'm having a spot of difficulty. 
nnir continually returns empty results:

Doing swish-e query ((query . kai))...
swish-e args: -f /home/aos/andyj/Mail/maildirs/.index.swish-e -w kai
Massaging swish-e output...done
Search produced empty results.
gnus-group-read-ephemeral-group: Couldn't request group: Search
produced empty results.

However, a swish-e search at the command line returns e.g.:

swish-e -f /home/aos/andyj/Mail/maildirs/.index.swish-e -w kai
# SWISH format: 2.4.0
# Search words: kai
# Removed stopwords: 
# Number of hits: 12
# Search time: 0.068 seconds
# Run time: 0.118 seconds
1000 Trash/cur/1067995483.M165311P9958Q0.tazman.Princeton.EDU:2, \
"1067995483.M165311P9958Q0.tazman.Princeton.EDU:2," 160366
633 Jacobson/cur/1068008269.M460437P11971Q0.tazman.Princeton.EDU:2, \
"1068008269.M460437P11971Q0.tazman.Princeton.EDU:2," 577481
...

I suspect nnir-swish-e-remove-prefix.  The group names should be Trash
and Jacobson (right?) and so I've been assuming that prefix == "" is
correct.  Various permutations of the default ("~/Mail",
"~/Mail/maildirs") don't work either.  Can nnir understand the "/cur/"
business above, which I suppose is part of the maildir protocol?  Any
other ideas?

Thanks!

  Andy