Seeking help with ORA-03113, ORA-01041, exp

Trying to perform a full export of a database, I get the following. This is repeatable and fails at the same point every time.

  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

  EXP-00008: ORACLE error 3113 encountered
  ORA-03113: end-of-file on communication channel
  EXP-00008: ORACLE error 1041 encountered
  ORA-01041: internal error. hostdef extension doesn't exist
  EXP-00000: Export terminated unsuccessfully

I also have in the alert log:

  Fri Apr 02 20:55:08 2004
  found dead shared server 'S000', pid = (10, 9)

And a trace file containing:

  Dump file f:\oracle\admin\ucbp\udump\ucbp_s000_2360.trc   Fri Apr 02 20:55:04 2004
  ORACLE V9.2.0.1.0 - Production vsnsta=0   vsnsql=12 vsnxtr=3
  Windows 2000 Version 5.0 Service Pack 4, CPU type 586   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   Windows 2000 Version 5.0 Service Pack 4, CPU type 586   Instance name: ucbp

  Redo thread mounted by this instance: 1

  Oracle process number: 10

  Windows thread id: 2360, image: ORACLE.EXE

• 2004-04-02 20:55:04.000
• SESSION ID:(27.8143) 2004-04-02 20:55:04.000 04/02/2004 20:55:04 UNWIND with no STOPEXIT active.

  04/02/2004 20:55:04 UNWIND with no STOPEXIT active.

And finally an CORE.LOG file which I will not include in its entirety but seems to indicate an access violation:

  Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production   Process Id: 0x00000450 Thread Id : 0x00000938 Time : Fri Apr 02 20:55:04   Excp. Code: 0xc0000005 Excp. Type: ACCESS_VIO Flags: 0x00000000

Seeking advice,

Allan

--
"The lyf so short, the craft so long to lerne." -- Chaucer