xml parser - xslsample

I am running Oracle 8.1.7 on NT. Any ideas why I am getting this error on the xslsample? I have loaded the xml plsql parser files and the xslsample procedure without errors. User has javauserpriv and javasyspriv roles.

omor>execute xslsample('d:orant\xdk\plsql\demo\sample', 'family.xml',
'iden.xsl', 'family.out', 'errors.txt');
BEGIN xslsample('d:orant\xdk\plsql\demo\sample', 'family.xml', 'iden.xsl',
'family.out', 'errors.txt'); END;

*
ERROR at line 1:

ORA-29540: class oracle/xml/parser/plsql/XMLParserCover does not exist
ORA-06512: at "OMOR.XMLPARSERCOVER", line 0
ORA-06512: at "OMOR.XMLPARSER", line 57
ORA-06512: at "OMOR.XSLSAMPLE", line 20
ORA-06512: at line 1