> I suggest putting a breakpoint in db.pas for assignments to
> TParam (.SetAsVariant, .SetAsString and .SetAsWideString) to
> see if you can see where the blank string is coming from.
> (In particular be on the look-out for "Unassigned" variants
> coming from IBO - there are some differences in handling of
> these between TDataSet and TIB_DataSet that seem like they
> could cause a problem. Note that an Unassigned variant will
> convert without error to a blank string (or zero number).)
>
> (Which is to say that I do not think your suggested fix is
> truly safe - it may hide other/real problems. We need to
> isolate why you are getting a blank string in this situation.)
>
> --
> Geoff Worboys
> Telesis Computing
>

I also thought that my method of closing all datasets of the transaction could be changed to closing them in a specific order rather than just via the count. If I clos the IBO stuff first, this may avoid this error.
Alan