Most Enigma's on DGS boxes use a different bootloader from the standard DGS bootloader.
So if you want to go back to a DGS based image after using one of these Enigma's, you have to flash the standard DGS (PAL or NTSC) bootloader (uboot.img) first and than flash the other images (all_noboot, kernel_root, db, welcome), or flash an all image.