External Display problem

HI, i have a problem with an external display connected with VGA to my MBP retina using an adaptador to thunderbolt.

i used to have different desktops in each screen, so if i changed from desktop "3" to desktop "2" in the external display, the desktop in the macbook display used to stay in the desktop "1" that i was using, now, if a change from one desktop to another (for example using gesture) booth screens are affected, son i have the same number of desktops in each screen and if a want to change in one screen i can't leave the other one in the desktop i was using.

just to be clear, the screens are not in mirroring, they are separated, only that the changes of desktop in one screen also affects the other one (the content of each desktop is not the same)

thank you for any answer