I just test another game and in this, the sleep mode works perfectly, so I think the problem is in FFVIII.
Here some status:
Game ID: SLPS 02180
Number of Eboot files: 1
Size De-compressed: 2.06GB
This version was converted the 4 disc in 1.
I don't have this ''multi ipl'' in my psp and I don't found this option im my m33 recovery config.