Out of curiosity is that card made by someone other than Sony? Third party cards such as ones made by Intec and Pelican have a nasty habit of being flaky- one is much better off using actual Sony memory cards.
I would suggest taking that memory card out and fully power down the system (turn the switch off on the back), leave it like that for a minute or so and then turn it back on. Then try a game without the memory card. If it works I would go get a new memory card as that one is not working right at all.