COPY FROM command v8.1.4

We are having some serious problems with the PostgreSQL COPY FROM command
and we have no clue what to do with this at this point. I think we need to
ask for 'guru' help in diagnosing this problem. Here is exactly what we are
doing:

We have a table with 12028587 records in it.
We do a COPY TO file of the records for this table.
We count the number of records in the file, it has 12028587 lines.
We do a COPY FROM that file into a table with identical structure as the
first table.
We count the number of records in the second table and there are only
12028538 records.
We do another COPY FROM same file onto a different database on an identical
table and this time there were 12028487 records in the count.

Another symptom of this problem is that when we do a pg_dump to file and
then a pg_restore from that file (only on large databases 20+ Gb) the
restore also loses about 100-300 records in the largest tables (the table in
question has 12+ and 6+ million records). The commands used were:

pg_dump -p <port> -U postgres -Fc -f <file> <db_name>
pg_restore -p <post> -U postgres -d <db> <file>

We are using PostgreSQL version 8.1.4 with SLES (suse enterprise linux with
SP3 - 9.3) running on 2 Opteron chips with 16 GB of memory.

Any help in diagnosing or resolving this problem is GREATLY appreciated.