cicerotw schrieb:

>> AFAIS this hasn't nothing to do with DoubleBuffering. You have (ok, IBO
>> has) a Font which is already 'nil' at destruction time. Hmmm... but
>> unfortunately from where I'm typing I cannot look at the source now...
>>
>> m.th.
>
>
> Then perhaps there is more than one problem here.
>
> If I open a simple form with a TIB_Grid I can open the TIB_Query connected to the TIB_grid and it displays the data correctly. If I then close the query I get the error ...
>

Sure, there is more:

- THackCustomGrid is wrong for D2009: the underlying class definition
has changed (see TCustomGrid, the definition must be the same, else
some you get access violations, because Pointers are wrong)
- Custom Double Buffering: no need for it anymore and a source of
errors in D2009 (comment out PaintWindow(), Paint(), WMPaint())

--
Andreas