If a slot is faulty, you can sometimes get away with it. Depends if you need to use all the slots or not. E.g. my board has six slots, I only use 3 (3x2GB sticks). So if any of the 3 that I'm not using are faulty, doesn't really matter. I mean yeah it sucks, and if your mobo is under warranty then def replace it, but I'd say it's ok to still run it.