When I use
extractvalue(XML_DOC, '/tariffInfo/tariff')
on ORACLE 9.2 I get ORA 19026 - message.

But on ORACLE 10g same instruction works fine.
The xmltype has the following contents:
...
<tariffInfo>
<tariff rvcd="2003">Doppeltarif</tariff>
<statisticGroup rvcd="2000">Gewerbe</statisticGroup>
<invoiceType rvcd="2000">Haushalt/Gewerbe</invoiceType>
</tariffInfo>
...
I expect to get "Doppeltarif".
Any idea?