Unable to name "middle-level" dataset elements

Hi,

I have a hierarchy of data sets reflected in the directory structure a file system, but I cannot find any way to control the name of the "middle" dataset elements (there are three levels of dataset elements) which correspond to -- and are named after -- the directories containing the data files, e.g., "saa/Products/netcdf/sst50" near the bottom of this email.

The second and last paragraph of "Reflect hierarchy of your dataset collection in your catalog" at http://www.unidata.ucar.edu/projects/THREDDS/tech/cataloggen/CatalogGenConfig.html implies I have control over the naming of these dataset elements, but I'm unable to figure out how.

Here is my XML configuration file:

<!DOCTYPE catalog SYSTEM "http://www.unidata.ucar.edu/projects/THREDDS/xml/CatalogGenConfig.0.5.dtd">
<catalog name="my data" version="0.6">
  <dataset name="SAA netCDF Products" dataType="Grid">
    <metadata metadataType="CatalogGenConfig">
      <catalogGenConfig type="Catalog">
        <datasetSource name="ds source" type="Local" structure="DirTree" accessPoint="/data/www/html/dods/saa/Products/netcdf/">
          <resultService name="DODSserver" serviceType="DODS" base="http://panther.ngdc.noaa.gov/cgi-bin/dods/nph-dods/dods/" accessPointHeader="/data/www/html/dods/"/>
          <datasetNamer name="netCDF namer" type="RegExp" addLevel="false" matchPattern="([^\/]+)\/([^\/]+)\.cdf$" substitutePattern="nc $1 $2"/>
          <datasetFilter name="My Test" type="RegExp" matchPattern="\/.+\.cdf$"/>
        </datasetSource>
        <datasetNamer name="dir namer" type="RegExp" addLevel="false" matchPattern="(.*)" substitutePattern="dir $1"/>
      </catalogGenConfig>
      <datasetNamer name="dir namer" type="RegExp" addLevel="false" matchPattern="(.*)" substitutePattern="dir $1"/>
    </metadata>
  </dataset>
</catalog>
And here is an excerpt of the generated output:
[mao@panther THREDDS]$ /usr/java/j2sdk1.4.1_02/bin/java -classpath cataloggen-0.6.jar:thredds.jar:jdom-b8.jar:dods.1.1.1.jar thredds.cataloggen.CatalogGen file:///home/mao/THREDDS/saatest.xml trash; head trash
readMetadataContent=[Element: <catalogGenConfig [Namespace: http://www.unidata.ucar.edu/thredds]/>]
Catalog read successfully (file:///home/mao/THREDDS/saatest.xml):
Message=----Catalog Validation version 0.6.02
  **Dataset (3) (SAA netCDF Products): is not selectable and does not have nested datasets

CatalogGen: catalog written to trash.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE catalog SYSTEM "http://www.unidata.ucar.edu/projects/THREDDS/xml/InvCatalog.0.6.dtd">
<catalog xmlns="http://www.unidata.ucar.edu/thredds" xmlns:xlink="http://www.w3.org/1999/xlink" name="my data" version="0.6">
  <dataset name="SAA netCDF Products" dataType="Grid">
    <service name="DODSserver" serviceType="DODS" base="http://panther.ngdc.noaa.gov/cgi-bin/dods/nph-dods/dods/" />
    <dataset name="saa/Products/netcdf/sst50" serviceName="DODSserver">
      <dataset name="nc sst50 20030405_090000" urlPath="saa/Products/netcdf/sst50/20030405_090000.cdf" />
      <dataset name="nc sst50 20030401_210000" urlPath="saa/Products/netcdf/sst50/20030401_210000.cdf" />
      <dataset name="nc sst50 20030329_090000" urlPath="saa/Products/netcdf/sst50/20030329_090000.cdf" />
      <dataset name="nc sst50 20030325_210000" urlPath="saa/Products/netcdf/sst50/20030325_210000.cdf" />
[mao@panther THREDDS]$ grep dir trash
[mao@panther THREDDS]$
(The grep is looking for "dir ..."  name attribute values generated
from the "dir namer" datasetNamer element.)

Thanks,

Mark