If it is an original box flash it with an original image from dreambox update. If its a clone it probably came with some ramdom image on it anyway so makes your request well irrelevant just flash a based team image.
Never known that and dont understand how it manages to do that because the flash is fully over written.
Only way this could happen is you have a settings backup on hdd or usb drives the image is picking up on when you reflash. It would usually ask about using a backup though so that would be a choice you made going through the basic setup stages.