CHMOD 2755 viewed as 2745

On SmartFTP 1.0.980 (I don't know with previous releases), on directories CHMODs 2755 are viewed as 2745 ! 8O
But if we try to set the CHMOD 2745, it sets 2745!

So if we do some tests on a directory playing with its CHMOD, and want to go back to what we think be 2745, we downgrade the CHMOD from 2755 to 2745.
It takes me some times to understand the issue. I could find it using other softwares which all give 2755 instead of 2745 (as displayed by SmartFTP 1.0.980).