Helen, thank you for your support. Here are some answers to your
questions:

1) I can see the existing value in the edit box
2) The column does not have any read-only flag set
3) When I open the dataset in IB_SQL, I cannot
edit the data. I tried to edit the data in IBConsole
and it works without problems.

Would you like me to send you the database, so you can try
yourself? There is nothing special in it however, you have
seen the create table statement.

Best regards
Mirco