This issue is to do with how Access returns the SQL datatype from the database on the key. To stop this tick the following attribute within your Interbase ODBC datasource set-up:
Once reconnected you should see the data. It should be mentioned that setting this could cause other applications to have problems with the data. For a full description of this configuration and the behaviour of the driver please reference the ODBC-Interbase Driver User Guide:
Oracle is a registered trademark of Oracle Corporation and/or its affiliates.