DOCBOOK: Newbie question

[Steven Gardner <sgardner@pdxinc.com>]

I know this is probably stupid and I probably have things set up wrong
but could you possible give me a hint.

I run a test document 

nsgmls -sv -E 1000 sample-docbook.xml

I think it is finding the correct DTD but I get a set of the following
errors for every file in the ent directory

...
nsgmls:/home/steve/doctools/DocBookXML/ent/iso-lat2.ent:55:18:E: "X0134"
is not a function name
nsgmls:/home/steve/doctools/DocBookXML/ent/iso-lat2.ent:56:19:E: "X0137"
is not a function name
nsgmls:/home/steve/doctools/DocBookXML/ent/iso-lat2.ent:57:19:E: "X0136"
is not a function name
nsgmls:/home/steve/doctools/DocBookXML/ent/iso-lat2.ent:58:19:E: "X0138"
is not a function name
nsgmls:/home/steve/doctools/DocBookXML/ent/iso-lat2.ent:59:19:E: "X013A"
is not a function name
nsgmls:/home/steve/doctools/DocBookXML/ent/iso-lat2.ent:60:19:E: "X0139"
is not a function name
nsgmls:/home/steve/doctools/DocBookXML/ent/iso-lat2.ent:61:19:E: "X013E"
is not a function name
...

Thank you for any and all assistance.

Steven Gardner
PDX, Inc.