> For quite a while, we have been finding records that violate constraints on them, such ass NOT NULL fields containing
> NULLS, fields with [CHECK (MyFiled = 'Y' or MyField = 'N')] with some other value in them. This is an old database, so
> the tables that showed this behavior had been manipulated plenty of times over the years, something may have been
> "unclean" about them. Anyway, we relatively recently just added a table to the database. One of the fields we call
> BBLShare, which is defined [BBLSHARE Numeric(15,3) Default 0 NOT NULL], has just turned up a NULL value. This table
> links to no other tables and only one application writes to it. The application explicitly sets BBLShare to 0, even
> though it will default to that. What could POSSIBLY have caused this to happen?

Which FB version ?
How do you know there are NULLs and not Zeros ?
Perhaps you added that column to already populated table ?

Ivan