if you want to enable Port1, you need d2x v10-alt OR an old cIOS v4 or v5.1 from Hermes.
note that if you use 10-alt (the revision 53), EmuNAND will have issues.
Note that if you enable "dual port" you MUST NOT use usb as path for your ressources (covers, music, theme, configs, etc.)
To be safe, ALWAYS use SD card for homebrew and files, only the games on USB.