If a card act's up like that, get rid of it, don't even try to find out what's wrong with it. If there's nothing on the card you need to retrieve, just throw it away and get another one.
No, first find out if it is indeed the card at fault, and not the card reader, usb terminal or a malfunctioning driver causing the problem.
It's okay to get another card, but don't throw the first one away until you know what is going on. Sometimes the problem is something other than the card.