vacuum error - 6.4.2 database..

Hi,

I did vacuum a database that I previously loaded 'heavily' with data and
got the following results and got it everytime I repeat vacuum:
elmu=> vacuum;
NOTICE:  BlowawayRelationBuffers(annex_log, 58): block 184 is referenced
(private 0, last 0, global 1)
pqReadData() -- backend closed the channel unexpectedly.
        This probably means the backend terminated abnormally before or
while processing the request.
We have lost the connection to the backend, so further processing is
impossible.  Terminating.

I am wondering now, that is this a constency problem, if so I'm really
worried about the situation. Do you know about any bugs of 6.4.2 like
this?

        THnaks

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