Hans,

From this callstack it is clear to me that you have hooked into an OnChange
event of a data aware control. By doing this you should check the state of
the dataset before assigning the text value of 'DCT' to your
TStringField.AsString property.

Take a close look at the callstack below and at the whole one in your email
you will see it has nothing to do with CachedUpdates and some problem in
IBO. It is coming from your application.

DatabaseError('Dataset not in edit or insert mode',nil)
TIBODataset.InternalSetFieldData($1761234,$12D44F)
TIBODataset.SetFieldData(???,???)
TDataSet.SetFieldData($1761234,$12D44F,True)
TIBODataset.SetFieldData(???,???,???)
TField.SetData($12D44F,True)
TStringField.SetAsString('DCT')
{
The next line is from YOUR app code.
}
TFMain.DispatchNewNoteTruckNoChange(???)

TCustomEdit.Change
...

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