Gaming Local multiplayer not working

[C_Roma]

Hi, i'm trying to play lotr conquest for the nds between a nintendo 2ds and a ds lite.

The problem is that when the characters show in order to select one, the screen says that we lost the connection.

The 2ds is using a r4 flashcart Gold Pro with the latest kernel. The ds lite a r4 for the 3ds (supports dsi).

-Other games play nice.
-I changed the flashcarts between the two consoles and tried with a ds fat.
-Both kernels are up to date.
-Tried others roms...

Any suggestions?

Thanks in advance.