When indexing on a date field ensure you use the expression DTOS(DateField)
This will make the date "index friendly". Does this solve the problem.

There was also a recent thread about the use of indexing on deleted(). If you table doesn't get too many deletes, you may not have to use it.

>Does anyone has experience/problems with a primary based upon a date field with filter on deleted(). I have a table which has the primary index set-up using database designer as above. I would input same date (i.e. like 01/01/1999) two or more times. I expected to receive an error message. Once I removed the deleted() filter then I got what I expected.