w/D3.02 and IBO 4.2Hd:

In TIBODataset.InternalSetFieldData:

...

{$IFDEF IBO_VCL40_OR_GREATER}
largeint(tmpData^) :=
Round( ScaleExtended( pdouble(Buffer)^, -SQLScale ));
{$ELSE}
comp(tmpData^) :=
Round( ScaleExtended( pdouble(Buffer)^, -SQLScale ));

'IB_Utils.ScaleExtended' has input of 42.383333333...

takes the abs of AScale {= -8} ... and returns 4238333333

throwing 'invalid floating point...' in assignment to the
comp(tmpData^), as far as I can see...

{ also, SQLTYPE = 581, if that matters... }

This is occurring in a BDE-to-IBO coversion Table.BeforePost method
which is unchanged during the last year of use, where a util function
of mine is assigning a double to DataSet['MyFloatNum']...