Oracle Database Backup Failed

Hi my production database backup run everyday,I am using 9.2.0.1.0 Oracle version. But suddenly database back failed for 3 days and then it again start working properly. I am not sure what will be exact reason,I have gone through LOG created when database got failed,Here is Log:

Connected to: Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.1.0 - Production
Export done in WE8MSWIN1252 character set and AL16UTF16 NCHAR character set

About to export the entire database ...
. exporting tablespace definitions
. exporting profiles
. exporting user definitions
. exporting roles
. exporting resource costs
. exporting rollback segment definitions
. exporting database links
. exporting sequence numbers
. exporting directory aliases
. exporting context namespaces
. exporting foreign function library names
. exporting PUBLIC type synonyms
. exporting private type synonyms
. exporting object type definitions
. exporting system procedural objects and actions
. exporting pre-schema procedural objects and actions
. exporting cluster definitions
EXP-00056: ORACLE error 600 encountered
ORA-00600: internal error code, arguments: [kpotcpop1], [], [], [], [], [], [], []
ORA-19206: Invalid value for query or REF CURSOR parameter
EXP-00056: ORACLE error 600 encountered
ORA-00600: internal error code, arguments: [kpotcpop1], [], [], [], [], [], [], []
ORA-19206: Invalid value for query or REF CURSOR parameter
EXP-00000: Export terminated unsuccessfully


    I searched online and many are suggesting to run catmeta.sql .Please help me asap as it's very important to fix production issue.