We have come across some data in one of our clients databases that
violates an integrity constraint, yet has not been picked up by firebird
or even when a gfix -v -full or gfix -mend -full has been run on the
database.

The table structure is shown below (from IB_SQL), the data in question
was ('282 12345', 'Jett Home Loans', NULL, NULL) there were twwo
rows with this data in the table.

We have seen this only once before, has anyone out there seen this
before or know of why it could happen?

The client is running FB 1.0.1

CREATE TABLE MBUSERCOMPANY (
USERCOMPANYKEY CHAR( 20 ) NOT NULL
, COMPANYNAME VARCHAR( 75 )
, TRADINGNAME VARCHAR( 75 )
, COMPANYABN VARCHAR( 20 )
, CONSTRAINT INTEG_799
PRIMARY KEY ( USERCOMPANYKEY )
)

-Ryan