There seems to be an automatic caption reset based on foreign key settings:
Table A with two columns ID and MODIFIED_BY, where ID is the primary key and MODIFIED_BY a foreign key to table USER with a column ID, thus A.MODIFIED_BY -> USER.ID
During model merge from MySQL 5.0 to Oracle 10g the caption of A.MODIFIED_BY was reset to "ID".
Furthemore when merging that Oracle model to an existing Oracle 10g model without checking the attribute caption property in the property selection the caption in the target model is overwritten with "ID" nonetheless.
Apparantly the caption of foreign key attributes is automatically synchronized with the corresponding parent entity's primary key caption. Is it possible to deactivate this automatic synchronization?
Waiting for fix in a future release of Toad for Data Modeler.