Help requeted with abend.

I just tried to pg_dump a db of mine and recieved the following abend.
Can someone please give me some guidance as to what is going on?  I just
created the db yesturday as part of a db migration plan.

Thanks,

Chris

DB. 7.3.4
OS: RH ES 2.1

Error:
pg_dump: ERROR:  MemoryContextAlloc: invalid request size 4294967293
pg_dump: lost synchronization with server, resetting connection
pg_dump: SQL command to dump the contents of table "detpro2" failed:
PQendcopy() failed.
pg_dump: Error message from server: pg_dump: The command was: COPY
public.detpro2 (column list removed) TO stdout;