Flashback - Switching disks doesn't work

Created by: turboboy215

I understand there's a separate core for this game specifically, but when I try to play this game, it runs well right up to the point where it says to insert disk 2 after the title screen. No matter what I try, it simply just doesn't work - it flashes black for a second and then says insert disk 2 again. Tried pressing every button and nothing happens. On WinUAE for PC, switching to disk 2 causes the screen to go black for a while and then goes to the first cutscene as it should. Other multi-disk games I've tried work. What's the problem here?