ORA-29807: Specified oprator does not exist

I am using the DBCA to build a databse and at about 17% through the set up I get the error message ORA-29807: Specified oprator does not exist. I surched the web and found one sight that said it is a known bug and to just choose ignore. I am not sure about that. When I look at the createdbcatolog.log file this is what I get:
drop operator XMLSequence
*
ERROR at line 1:
ORA-29807: specified operator does not exist
any advice? :confused:

workaround:

1. Click Ignore and go ahead with DBCA (after invoking DBCA).

2. Go to the script catxml.sql and comment out the line which will run prvtxml.plb ( before invoking DBCA).