I think you are fighting with a "bug" of IBO, about what we have time ago discussed with Jason and Geoff Worboys.
Internally IBO uses a weak solution to scale the value to an integer, so since it multiplies the value for a power of 10 related to the number of decimal, and all this is done with currency type, it goes "out of range". If you don't need currency precision, since you are using them "AsFloat", try to define the column as "double" or something like this (I don't use such a type of fields, usually, so I don't remember the syntax).
Hope this will help (I'm in a hurry now, so sorry if I could not be more precise).
Regards
Marco Menardi

--- In IBObjects@y..., "helton_o" <helton_o@t...> wrote:
> Hi,
>
> I have the follow table in a IB database:
>
> CREATE TABLE Formulas
> (
> CodFormula SMALLINT NOT NULL ,
> DscFormula VARCHAR(15) NOT NULL ,
> CodVctoDesc SMALLINT NOT NULL ,
> Formula VARCHAR(150) NOT NULL ,
> Piso NUMERIC(18,2) DEFAULT 0 NOT NULL ,
> Teto NUMERIC(18,2) NOT NULL
> );
>
> When i try to assign a value to the field "Teto" (
> tblFormulasTeto.AsFloat
> := 999999999.99; ) i receive an error message "Invalid floating point
> operation", if i try to assign the value 899999999.99 it works fine.
>
> I'm using a TIBOTable and Dialect 3.
>
> Any sugestions ?
>
> Helton