xpointer woes

docbook-dtd-4.5b1 docbook-xsl-1.69.1 jdk-1.5.0_4, kubuntu-5.04 oXygen-6.1 
saxon-6.5.4

A little confused.

Why does xinclude / xpointer work on some elements and not others.

Example: informaltable works fine but attempting 
xpointer="element(<informaltable-id>/1/*)" or 
xpointer="element(<informaltable-id>/1)" does not assuming the table is 
followed immediately by a tbody and then row statement.

Would like to implement xpointer table row sets (hence the wildcard)

Appears xpointer=xpointer ... is not supported with my configuration.

Raymond