Ohhh thats a pitty. There are plans to implement it or depends on retroarchs development???

Hello,   I'm a new user of your fantastic distro, however after instalation (pi2 - sd 8gb) i'm facing a problem with saves. Playing mame roms, when i try to save state (pressing hotkey + y) i get the message: the core does not support save states. Can anyone tell me what i'm missing??   Thank you in advance.