[lleinado]

Do both. If you revert back to 1.5, at least you have all your system settings right where you left them and set to the way you like it. Do a data backup too so you don't need to redownload all the 1.5 apps again. After the backup, you need to remove or copy your backup to your PC as installing 2.1 DD03 first could wipe your SD card. Best to just put all the files on your PC anyway for safe-keeping. YOU NEED TO INSTALL DD03 FIRST! Sorry, but you do, to be able to flash the DD10 with all the cool wallpapers, etc. Good Luck!