I think when that certain someone took out your card they may have been a bit rough about it- the problem is in the slot itself, not the cards.
You may be able to continue on using slot 2 but you will most likely have to get the thing repaired, either by Sony or maybe you have a local game store that also does this sort of thing. Either way is going to cost you a bit of money (which i would make that "someone" pay).