European SNES carts don't work on clone systems?

[Tupin]

Okay, so I figured out getting a European copy of Super Mario All-Stars would be cheaper than finding an American copy, but I hear that some Nintendo published games like the European Donkey Kong Country don't work on the Retro Duo. Instead it shows a screen saying something about piracy or how the game wasn't meant for your system.

My question is, does Super Mario All-Stars have this? Oh, and European NES games work on the Retro Duo and similar systems, right?

[Mayhem]

It's because some PAL games are coded to refuse to work at 60Hz and instead you get the message on screen saying the game pack isn't designed for the system you're trying to play it on. Only on boot though. A SNES modded for 50/60Hz can be booted in 50Hz and then swapped to 60Hz afterwards on these games.

[Tupin]

It's because some PAL games are coded to refuse to work at 60Hz and instead you get the message on screen saying the game pack isn't designed for the system you're trying to play it on. Only on boot though. A SNES modded for 50/60Hz can be booted in 50Hz and then swapped to 60Hz afterwards on these games.
The thing is, I think some games work on clone systems, but others don't.

I've seen Super Mario Kart work on the Retro Duo, but when the American SNES version has trouble working, I'm not sure if it will.

Oh, and I'm pretty sure European NES games work on clone systems.

[ooXxXoo]

A 50/60 Hz switch can be installed on the RetroDuo as well for the SNES side, its fairly easy to do...I've done it....