Though technically non re-entrant... since any updates you make after application will not be recognized... it should still remove and replace any form and not create duplicate code like this, so this sounds like a bug, but it depends on your process.
To edit the form, make sure to click the edit button after highlighting the form in the properties inspector window. If you simply highlight and reapply over the old form it would not properly replace all of the other parts of the code, so that may be what happened in this case.
I will report it to the QA team to log as a bug and investigate a solution.
Did this help? Tips are appreciated...
