Can't Remove Games

I'm trying to reset all the games I downloaded back to the original 8, but I want to save the scores for the original 8 (I got 24k in tetris )

How would I go about doing this? When go to the games list, I click "Check All". Then I deselect the ones I want to keep, and I check the "delete" selector at the bottom. But they don't delete. When I go back to the games list, they are still there.

Do I have to chmod anything?

Thanks,
Alex