XML "X00E1 is not a function name" and "cannot generate system identifier"

Dear Friends,

I'm trying to understand the meaning of these autputs.

When I use DocBook XML V 4.2 the output is:

bash-2.05a$ openjade -t xml  -d 
/usr/local/sgml/dsssl/docbook-dsssl-1.78/html/docbook.dsl 
/usr/local/sgml/dsssl/docbook-dsssl-1.78/dtds/decls/xml.dcl artigo.xml
openjade:artigo.xml:83:15:E: end tag for "bibliography" which is not finished
openjade:/usr/local/sgml/docbook/4.1.2/ent/iso-lat1.ent:6:19:E: "X00E1" is not 
a function name
openjade:/usr/local/sgml/docbook/4.1.2/ent/iso-lat1.ent:7:19:E: "X00C1" is not 
a function name
...............

When I use DocBook XML V 4.2 the output is:

bash-2.05a$ openjade -t xml  -d 
/usr/local/sgml/dsssl/docbook-dsssl-1.78/html/docbook.dsl 
/usr/local/sgml/dsssl/docbook-dsssl-1.78/dtds/decls/xml.dcl artigo.xml
openjade:artigo.xml:83:15:E: end tag for "bibliography" which is not finished
openjade:/usr/local/sgml/dsssl/docbook-dsssl-1.78/html/../common/../common/dbl1no.dsl:2:66:W: 
cannot generate system identifier for public text "ISO 8879:1986//ENTITIES 
Added Latin 1//EN"
openjade:/usr/local/sgml/dsssl/docbook-dsssl-1.78/html/../common/../common/dbl1no.dsl:3:5:E: 
reference to entity "lat1" for which no system identifier could be generated
openjade:/usr/local/sgml/dsssl/docbook-dsssl-1.78/html/../common/../common/dbl1no.dsl:2:0: 
entity was defined here
................


In spite of this outputs, both converts the xml to htm, but I'm in doubt if I 
should to fix something.

For V 4.1.2I included in the docbook.cat the parameter:
SYSTEM "http://docbook.org/xml/4.1.2/docbookx.dtd" 
"/usr/local/sgml/docbook/4.1.2/docbookx.dtd"

And for 4.2
SYSTEM "http://docbook.org/xml/4.2/docbookx.dtd" 
"/usr/local/sgml/docbook/4.2/docbookx.dtd"



Another question:

I experimeted to remove the directory /ent and even in 
this case the openjade generate the htm files. 
Why?

When these files (iso-.....ent or ISO...) are used in the conversion process?


Thanks in advance for any suggestion,

Nei