The README.TXT file for DB2 XML Extender Version 7.1 says the following under "Considerations":
3. The default version of DB2 UDB is DB2 UDB Version 7.1. If you wish to use DB2 UDB Version 6.1 on AIX and Solaris systems, you should ensure that you are running with DB2 UDB V6.1 instance and with the DB2 UDB V6.1 libraries.
This is incorrect. The DB2 XML Extender is supported only with DB2 Version 7.1 and 7.2.
The files readme.aix, readme.nt, and readme.sun list Software Requirements of:
This is incorrect. The DB2 XML Extender requires DB2 Version 7.1 or 7.2.