ora-03113 error during update batch

We encountered the following error in the batch log file during a load of data into our database.
This error was encountered during the execution of single row SELECT statement
from different tables as well as during the update of a large table. This indicates that is is not
related to any particular SQL command or table. It occurred after approximately 7
hours of run time on one occassion, after approximately 12 hours on another.

 Error 1FFF0001 in routine load_ENCOUNTER,  ORA-03113: end-of-file on communication channel  SQL : insert into ENCOUNTER
(encounter_id,visit_number_hl7_producer_id,v

This is the substance of the trace file generated after the error was encountered:

 ORA_ROOT:[DB_REGEN.TRACE]ORASRV_BEQ_27E26C9C.TRC;1  This trace file was generated by ORASRV_BEQ_REGEN.COM  exit with STATUS = %X1000000C
 %SYSTEM-F-ACCVIO, access violation, reason mask=!XB, virtual address=!XH, PC=!XH, PS=!XL

This is all we know of the error based on searching Oracle tech support sites:

ORA-03113 end-of-file on communication channel

Cause: An unexpected end-of-file was processed on the communication channel. The problem could not be handled by the Net8, two task, software. This message could occur if the shadow two-task process associated with a Net8 connect has terminated abnormally, or if there is a physical failure of the interprocess communication vehicle, that is, the network or server machine went down. In addition, this message could occur when ALTER SYSTEM KILL SESSION or ALTER SYSTEM DISCONNECT SESSION were issued with the IMMEDIATE qualifier because, in those cases, the client's connection to the database is terminated without waiting for the client to issue a request.

Action: If this message occurs during a connection attempt, check the setup files for the appropriate Net8 driver and confirm Net8 software is correctly installed on the server. If the message occurs after a connection is well established, and the error is not due to a physical failure, check if a trace file was generated on the server at failure time. Existence of a trace file may suggest an Oracle internal error that requires the assistance of customer support.

We are not currently on any Oracle support contract. I would appreciate it if someone could identify
how this error is occurring and recommend a course of action.

We are running Oracle 8.1.7 on an OpenVMS 7.2-1 clustered platform. Received on Thu Oct 11 2001 - 14:05:12 CDT