Used the link you gave me, it won't reboot into recovery.
Furthermore, I installed ROM manager, and there (I supose) I made a backup.
I rebooted and it's doing "Android is upgrading" stuff.
So, after flashing a new rom, I just opet this same app, and use Restore from backup to restore to stock ROM, or I have to flash stock ROM first and then use Restore from backup option?
This may look way simpler than I thought.
i dont believe that would work since rom manager needs a Custom Recovery ato restore, i do read that our recovery didnt work with the european version
if it does work then you should download and install f6utilities make sure youre rooted and select installcustom recovery, then reboot into recovery. after that there is a back up and restore sectio, go there and backup to external SD card not the internal one. it should take about 800MB so make sure you have space.