That's what I'd thought. Having it work any other way would be impossible to do currently with such a small card, as the hardware would need to interpret the data being installed, and know what to put where, what files need to be clumped together, etc. I mean, it could be done, theoretically... but not on such a small size with currently-existing technology...Taking one mSD out or swapping the slots will make all the data unreadable (unless you put it back how it was originally).
That is what I mean, and GameStop only has a 7-Day warranty on used games, and... now that I think about it, When I first got it, the clear part on the front of the UMD case was indented at the bottom... Shit.and if the disk has a ring (i assume you mean it has like a big scratch that goes all around?) then the disk is dead one way or another. Toothpaste only works on the most miniscule scratches, if at all. and even then, most toothpastes cause more damage than they solve.
you'll have to get another copy or an iso to play from memorycard (its about 1,5gb in size)
do you have any kind of guarantee? maybe you could return it, because these games should be pretty much safe from scratch damage due to their umd nature. if it created a circular scratch all around, something with the umd casing has to be wrong. unless you somehow got sand into the umd case...