> In IBO4, I believe this code need some modifications since as BufferRowNum
> can assume negative, zero and positive values.
> Maybe,
> .......
> .......
> if (abs(DataSource.Dataset.BufferRowNum) >= 0) then begin
> if GridFields[ACol - 1].IsNull then AString := '<null>';
> end;
>
> works better.

Rather than use 0 (which is an assumption) it should be replaced by the
BofRowNum property of the dataset. In most cases it will be 0 but there are
those times it is less than or more than zero. It is also important to take
the BufferHasBof property into consideration as well.

The internal references and the external references for IBO buffering are
also virtualized so that filtering can take place as well.

Regards,
Jason Wharton
CPS - Mesa AZ
http://www.ibobjects.com