344 - Index not sorted

[Tim James]

I am getting this error when I attempt to execute the following

INSERT INTO CRheaders  
(Number,DateIssued,DateReceived,DateCompleted,Status,Supplier,TotalValue 
,TotalUnits,Comments) VALUES  
("16","6/4/04","00/00/00","00/00/00","0","241","0.00","0"," ")

The only field that is indexed is number which is also defined as unique

There is only one row in the table with a number value of "8999001".

I have reindexed the BO, deleted the db.ind file but all to no avail

Any ideas