Make sure the database is created with the same encoding.
Default for 7.3 would be SQL_ASCII and default for 8.x would be UTF-8 so make sure you created the new database to be imported into with the same encoding.
If that does not help, you'll need to capture the output of psql -f when you reload the database and check it for errors.
With the error information we can probably give you some more help.
