gimp 2.4.3 : size when creating new file

After a long time of research in the documentation of gimp, and on google, I could not find why, in the new version of gimp (2.4.3), when I create a new file after copying a part of an image (rectangular selection then edit>copy),  the size of the new file is no more set automatically to the size of the part copied... There is not any option in the settings menu of gimp that allows us to control that...

I wanted to know if I missed something or if it's normal ..?

Thank you to all of you,

Rafael