Backup your SD to a Backup folder on your PC BEFORE upgrading to a new Kernel

Format your SD with the Panasonic SD Formatter 3.1
Use these options :
FORMAT TYPE - FULL (OverWrite)
FORMAT SIZE ADJUSTMENT - ON

PRIMARY Kernel :
Extract these files from DSTTi-Clone YSMenu folder and copy to root of your SD :

Games folder
TTMenu folder
TTMenu.dat


DUAL BOOTING :
Download the latest Kernel from your carts website and extract to root of your SD.
Extract these files from DSTTi-Clone YSMenu folder and copy to root of your SD :

Games folder
TTMenu folder
TTMenu.dat
YSMenu.nds

Boot your carts Kernel, then load YSMenu.nds.