The version of psgml (1.2.3) shipped with RHL9 is hopelessly out of date. psgml 1.2.5 came out on April 19th 2002 (nearly a year ago). Importantly, 1.2.5 fixes some important bugs with XML validation, which does not work correctly in 1.2.3. Please update this very important tool for we docbook writers.
New package will appear in rawhide shortly.