Hi,
When I select regions in the Frame Buffer, these are secretly saved in the file.
When sending the scene to the render farm, these regions remain active and only they are rendered.
Sometimes it is not enough to delete them, by clicking the red [X] oder selecting "Remove All"
I would consider this as a major bug, because it secretly saves information in the file completely hidden from the user and it may cost a lot of time and money.
If this is a intentionally desired function, it must be possible to switch it off using a check box.