ERROR: could not access status of transaction on postgresql 8.0.3

I got this menssage:

ERROR: could not access status of transaction 3923741036
DETALHE: could not open file "/var/lib/pgsql/data/pg_clog/0E9D": No such file or directory

when I tried to dump a database on a engine 8.0.3 running on Red Hat 9.0 Linux.

I read about this, but most of then is on engine 7.4.x and none of the solutions resolve my problem.

Thanks

Malcus Imhof