Phil,

I guess one question is where are you reading your results from?

One difficulty is that when you assign properties/events of a
TIB_Column using FieldByName or Fields[], then you are assigning to
the column instance only on that particular TIB_Row (the TIB_Row used
to hold and interact with the currently selected row of the dataset).

Grids and some other operations (perhaps even your own) that are using
buffered datasets (TIB_Query) may be using BufferFields or
BufferFieldByName which references a different TIB_Row, and therefore
different column instances, instances that have not been assigned the
special OnGetText functions.

You are probably better of using calculated fields to display the
appropriate value. Not sure if TIB_ComboBox supports it, but
TIB_ComboBoxEnh (from my enhanced components) also supports this sort
of arrangment on TIB_Grid.

If you are not using TIB_Grid, then TIB_ComboBox (the IBO one) does
have the ability to display a different value to what appears in the
column - see the Items and ItemValues properties. (TIB_ComboBoxEnh
has support for this as well but implemented differently.)

Does this help?

Geoff Worboys
Telesis Computing