FIRSTLY THANKS THANKS THANKS - Along with FBReader these were my two wants !!!
Then apologies I have no way to test it, my pandora is not with me at the moment

So my comments are based on memory!
Have you implemented the keyboard ? - The way the G7000 (as I knew it - I owned one

) use to work was pop a cartridge in THEN press a key on the keyboard for the "type" of game - This would then select two player / or 1 player / or 1 player vs computer. I know the dingoo version had similar weird issue with joystick but it was because the keyboard had not been emulated so the emulator just randomly (seemingly) started any type of game.
He also mapped both controls to the same key sequence, and I think (not been back to dingoo for a while) he left it in that state.