> Would be possible to correct this problem ? I tried GFIX... -F, -V, -M
> .... and... nothing.

Either delete the whole row containing wrong blob-id, or just set it to null, i.e.
DELETE FROM tab WHERE id=...;
or
UPDATE tab SET blob_field=NULL WHERE id=...;

What version of FB/IB do you use ?

Ivan
http://www.volny.cz/iprenosil/interbase