I don't really know where my problem belongs, so I'll try to sketch it
here. Hopefully somebody can tell me if I should go to a Delphi
newsgroup or give more details here.

I've started to write a small WinForms application, using BDS 2006. It
should populate a ComboBox from the Employee database, using the
statements

mycombo.DataSource := mydataview;
mycombo.DisplayMember := 'Country';
mycombo.ValueMember := 'Currency';

If this is called I get an exception "couldn't be bound to the new
display member" (my translation from German). It seems to be specific
to the ComboBox - I can use mydataview as datasource to a DataGrid and
get correct results. So far it looks like a Delphi problem.

Only: if I replace the Firebird database with a MS Access database,
the problem disappears, the ComboBox shows the right data. Of course
with MS Access I must change all the database related components. But
there is no difference between using the Firebird .NET provider
(version 1.7.1) or the Borland Data Provider for Interbase. Both give
the exception. So at all events it doesn't seem to be the provider.

Firebird Version: 2.0.3, OS: Windows XP Professional.

So what could be wrong here and where should I look for help?

Thank you for looking at this,
Herta