No idea... But look at it this way... Every high score can be beaten so doing the levels again isnt a bad thing. Just means you know how to three star them easier.
Lets be honest it will not take you more than a weekend to do it 3 stars again if you have already 3starred the levels.

Best thing you can do is contact Miika or search this forum. I thought there was a thread about saved games.

I'd have to admit if i lost my scores id be gutted and i dont think id play it again. So knowing how to back it up would be a bonus.