My dsi action replay won't work on my dsi but it works on my ds. Why is that?

I heard that the DSi prevents the AR from working because of a kind of security system.

After you insert the AR device and turn on the system, you'll see the "Insert Game Cart" message blipping across the screen. From there you have to remove the AR device while your system is on and replace it with your desired DS game cartridge and then the "Start/GO" button will appear, fully functional and ready to operate.

Don't even bother trying to get the Code Manager to smarten up, just add and edit your desired codes manually from there on. After all newer software on the dsi when compared to the ds so datel may have to make a new AR for the dsi or.... ur AR may be bust as datel's build quality is not the best. So try the AR on older ds's if it works thn new sofware prevents it so you may have to buy a specific AR or if it dosnt work on a old ds thn u know u got a knackered up AR device.