Still see green arrows after synchronization

[Jonathan Ross]

I use Database > Synchronize Model and it completes successfully: I can see the changes in the Model successfully reflected in the database/scripts as expected. But when I go back to Database > Synchronize Model to synchronize new changes to the database and/or model, I still see the original "green arrows" from my previous synchronization. The SQL code also shows that Synchronize Model wants to apply the previous updates that already completed successfully in the previous synchronization. Many thanks for letting me know what I'm doing wrong or how to fix this.