Problem getting going with THREDDS aggregation server

THREDDS gurus:

We are trying to get the DODS aggregation server going using the 
thredds.war distribution.

I've got a very simple catalogConfig.xml file 
<http://stellwagen.er.usgs.gov/rps/catalogConfig.xml> that just 
contatenates two OpenDAP-served files along the record dimension. This 
file is installed in $TOMCAT_HOME/content/thredds/dodsC

When I access <http://coast-enviro.er.usgs.gov:8080/dodsC> and click on 
(for example) the .dds I get:

Error {
   code = 1;
   message = "Dataset not found in catalog; urlPath= <roms_sed/sed025/history>";
};


I gave the catalogConfig.xml to a colleague who already has a 
aggregation server running and he said it works fine, so the problem 
doesn't seem to be the ability of our server to serve the DODS files, 
and it doesn't seem like there is a problem with the catalogConfig.xml 
either. 

Is there something else we have to configure?   I didn't do anything 
with /thredds/catalog.xml, for example, because I wasn't interested in 
getting the catalog server going, only the aggregation server.

I looked at the log files, and they just say the same thing as the error 
message above.

Seems like we must be missing something simple!


--
Richard P. Signell  
U.S. Geological Survey       Phone: (508) 457-2229
384 Woods Hole Road          Fax:   (508) 457-2310
Woods Hole, MA  02543-1598