recovering data from pgsql 6.1 installation

Hi!

The problem:

We've had the pgsql 6.1 installation made by previous admin.  Due
instability, I am to upgrade it to the current one.  Having no previous
experience with pgsql, I've forgot to dump db :(

Now, neither pgsql 6.3, 6.2 or even 6.1 can't read the db.

$ psql mailing
Connection to database 'mailing' failed.
PQexec() -- Request was sent to backend, but backend closed the channel
before responding.  This probably means the backend terminated abnormally
before or while processing the request.

How I can find more verbose error message?  What are the possible ways to
recover the data?  Pointers to TFM would be very helpfull.

--
SY, Andrey V Khavryutchenko    http://www.kbi.kiev.ua/~akhavr

Shick's Law:
    There is no problem a good miracle can't solve.