snafoo in tools, help?

[Gregory Leblanc <GLeblanc cu-portland edu>]

I just hit a snag trying to validate a doc here at the office.  I'm running
RH6.2, with the following packages installed:

[gleblanc@grego1 gleblanc]$ rpm -q docbook jade jadetex sgml-common
stylesheets gnome-doc-tools 
docbook-3.1-3
jade-1.2.1-9
jadetex-2.7-2
sgml-common-0.1-7
stylesheets-0.13rh-4
gnome-doc-tools-1.0-1
[gleblanc@grego1 gleblanc]$ 

I've got a document using the PNG variant 1.1.  When I try to validate it
using nsgmls -s doc.sgml, I get these errors:

nsgmls:/usr/lib/sgml/dbcent.mod:54:0:E: cannot open
"/usr/lib/sgml/iso-amsa.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:61:0:E: cannot open
"/usr/lib/sgml/iso-amsb.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:68:0:E: cannot open
"/usr/lib/sgml/iso-amsc.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:75:0:E: cannot open
"/usr/lib/sgml/iso-amsn.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:82:0:E: cannot open
"/usr/lib/sgml/iso-amso.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:89:0:E: cannot open
"/usr/lib/sgml/iso-amsr.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:96:0:E: cannot open
"/usr/lib/sgml/iso-box.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:103:0:E: cannot open
"/usr/lib/sgml/iso-cyr1.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:110:0:E: cannot open
"/usr/lib/sgml/iso-cyr2.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:117:0:E: cannot open
"/usr/lib/sgml/iso-dia.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:124:0:E: cannot open
"/usr/lib/sgml/iso-grk1.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:131:0:E: cannot open
"/usr/lib/sgml/iso-grk2.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:138:0:E: cannot open
"/usr/lib/sgml/iso-grk3.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:145:0:E: cannot open
"/usr/lib/sgml/iso-grk4.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:152:0:E: cannot open
"/usr/lib/sgml/iso-lat1.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:159:0:E: cannot open
"/usr/lib/sgml/iso-lat2.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:166:0:E: cannot open
"/usr/lib/sgml/iso-num.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:173:0:E: cannot open
"/usr/lib/sgml/iso-pub.gml" (No such file or directory)
nsgmls:/usr/lib/sgml/dbcent.mod:180:0:E: cannot open
"/usr/lib/sgml/iso-tech.gml" (No such file or directory)

Lo and behold, those files aren't there.  All of the installed packages
verify (well, except for stylesheets, which says that cygnus-both.dsl is
changed, which is good).  Sounds like I'm missing some enties, but I'm not
sure what package these should come from.  Any ideas?  Thanks,
	Greg