Catalogs and DB XML

[Alexander Kirillov <kirillov math sunysb edu>]

First: indeed, in my previous attempt xsltproc was fetching DTD from the
net, which slowed it down. So, this time I tried to force it to use
local DTDs, by doing
export SGML_CATALOG_FILES=/etc/sgml/catalog
xsltproc  --catalogs -o gnome-app-template.html
/usr/share/sgml/docbook/xsl-stylesheets-1.44/html/docbook.xsl
gnome-app-template.xml

And it seems that I hit a bug in docbook-dtd412-xml package. I get
pelnty of error messages like
 
 /usr/share/sgml/docbook/xml-dtd-4.1.2/dbcentx.mod:56: warning: failed
to load external entity
"/usr/share/sgml/docbook/xml-dtd-4.1.2/ent/iso-amsa.ent"
%ISOamsa;

Quick check shows that the file
/usr/share/sgml/docbook/xml-dtd-4.1.2/dbcentx.mod
contains lines like 

<!ENTITY % ISOamsa.module "INCLUDE">
<![%ISOamsa.module;[
<!ENTITY % ISOamsa PUBLIC
"ISO 8879:1986//ENTITIES Added Math Symbols: Arrow Relations//EN//XML"
"ent/iso-amsa.ent">
%ISOamsa;
<!--end of ISOamsa.module-->]]>

which - as far as I can see - refer to the file ent/iso-amsa.ent, and
such a file does not exist. Instead, I do have file ent/ISOamsa.ent.  

Is it indeed a bug or am I missing something? 
Can anyone with working XML catalogs check what happens on his system? 

Thanks,
Sasha