Help with Final Fantasy CC: Ring of Fates

Hey,I downloaded the FFCC Rom, and it plays just fine. But sometimes, when I enter a door or another area, the "Thanks for playing!" screen pops up and I get thrown back into the main menu. Does anyone know what might cause this, and how I could solve this? Btw, I use an R4.Many thanks.

it's a copy protection system, theres a few threads about it.

Yes and if you add the bypass action replay code, you can keep playing for several hours. It works.