News Mario Bros saves from NDS-bootstrap to R4?

I'd like to transfer progress from NSMB Im playing on DSi via NDS-bootstrap + twilightmenu to a o3Ds with R4isdhc flashcart (with Ysmenu). I'm unable to find the right file on the DSi SD card. There IS a sav file with the right name in /roms/nds/saves but the date is wrong and it doesn't work on the 3ds.

Any tips? Thanks!