JBDS marks imported model as invalid

When I generate view model from the DDL (comment.ddl in the attachments), JBDS shows that model contains errors. However, when I click on the transformation editor, the model is updated, but still not valid. After that, I am not able to click on the Save/Valid SQL button so I have to add and remove the character to the transformation editor. When I click on the Save/Valid SQL button and save the model, the model looks validated and errors are gone. Why is the view model not valid after generated? I have uploaded video to the attachments.

This has to be specific for that DDL (comment.ddl) because for another DDL(description.ddl), a view model is already valid after generated.