> A client's 600 Mb database, running of FB 1.01, refuses to
> back up with the error "cannot find back record version
> (291)."

> Validation check produces no errors. Backing up with checksum,
> garbage collection and limbo transactions switched off makes
> no difference.

> The table on which the back up seems to fail gives errors if
> I try to empty it or drop it ("software consistency check").

Hi Roger,

You could give DBak a try:
http://www.telesiscomputing.com.au/dbk.htm

Use the Rebuild option to try and reconstruct a copy of the
database.

DBak has various "Process Options" for ignoring errors which,
if nothing else, may make it easier to recover as much data
as possible. I have found it useful for some corruption
problems in the past.

I would also be interested to know how it copes in this
situation :-)

(PS. As already advised: Be sure to keep a copy of the
problem database - you may be able to get help from other
sources if nothing else works.)

--
Geoff Worboys
Telesis Computing