[thredds] Direct dataset accessing

Hi John,

I have a question about THREDDS catalog.
When I directly access a direct dataset using http://.../catalog.xml?dataset='dataset id' e.g.:
http://motherlode.ucar.edu:8080/thredds/catalog/fmrc/NCEP/GFS/Alaska_191km/runs/catalog.xml?dataset=fmrc/NCEP/GFS/Alaska_191km/runs/NCEP-GFS-Alaska_191km_RUN_2008-02-11T06:00:00Z
then I back to access
http://motherlode.ucar.edu:8080/thredds/catalog/fmrc/NCEP/GFS/Alaska_191km/runs/catalog.xml
it will show only one dataset under this level, that is fmrc/NCEP/GFS/Alaska_191km/runs/NCEP-GFS-Alaska_191km_RUN_2008-02-11T06:00:00Z
But this is not right , it should be at lease eighty datasets under this level.
If I do not use http://.../catalog.xml?dataset='dataset id', instead with  http://.../catalog.html?dataset='dataset id' at the beginning, everything is normal. My work is about interoperability between CSW and THREDDS, and in some cases, I need to get a direct catalog xml document using this way. Could you please help me to find out what's the problem with it?

Have a good day!

Chengfang