Problem while restoring a database from SQL_ASCII to UTF-8

Hi,

I have a database in SQL_ASCII Encoding format from Postgresql-7.4.19. I
have migrated to Postgresql-8.4.9 and to UTF-8 and want to restore this
database in UTF-8 encoding. I am facing problem in restoring it as UTF-8.
I have 29 tables in the database, out of which it is unable to restore 3
tables. It gives the following error:

pg_restore: [archiver (db)] Error while PROCESSING TOC:

pg_restore: [archiver (db)] Error from TOC entry 83; 0 40257 TABLE DATA
document postgres

pg_restore: [archiver (db)] COPY failed for table "document": ERROR:
invalid byte sequence for encoding "UTF8": 0xe92034

HINT: This error can also happen if the byte sequence does not match the
encoding expected by the server, which is controlled by "client_encoding".

CONTEXT: COPY document, line 15

pg_restore: [archiver (db)] Error from TOC entry 88; 0 40271 TABLE DATA
attribute postgres

pg_restore: [archiver (db)] COPY failed for table "attribute": ERROR:
invalid byte sequence for encoding "UTF8": 0xe90931

HINT: This error can also happen if the byte sequence does not match the
encoding expected by the server, which is controlled by "client_encoding".

CONTEXT: COPY attribute, line 909

pg_restore: [archiver (db)] Error from TOC entry 90; 0 40277 TABLE DATA
revision_state postgres

pg_restore: [archiver (db)] COPY failed for table "revision_state": ERROR:
invalid byte sequence for encoding "UTF8": 0xe9e96e

HINT: This error can also happen if the byte sequence does not match the
encoding expected by the server, which is controlled by "client_encoding".

CONTEXT: COPY revision_state, line 363

I have checked these three tables and I found that these tables contain
special characters as values for some attributes for some records. I tried
to use the procedure mentioned in the following link, which didn't worked
for me:

http://archives.postgresql.org/pgsql-admin/2004-07/msg00206.php

I also have blobs in one table in this database, but I don't think/see any
issues with them. Is there a way to restore the database from SQL_ASCII to
UTF-8? Is there a way to restore the database as SQL_ASCII and then convert
the Encoding to UTF-8? What is the consistency level? Or are there chances
of getting garbage?

Kind Regards,

Manoj Agarwal