This is a problem with Intermedia. I'd recommend installing the patchset to bring you up to 8.1.7.4, there are many Intermedia fixes in it.
If I remember correctly even after installing 8.1.7.4 I still had to drop and reinstall the Intermedia subsystem. If you have access to Oracle Metalink the DocID for documentation on how to do that is in Note:131023.1. Note typo in the doc "drcrsyst.sql" should be "dr0csys.sql" and takes three parameters: CTXSYS user's password, CTXSYS tablespace (DRSYS), and temporary tablespace for the CTXSYS user (TEMP).
I also have a hazy recollection that even after the reinstallation of Intermedia the default preferences setup script does not get run. That script is in $ORACLE_HOME/ctx/admin/defaults/drdefus.sql.
