MY PSP CAN'T READ MY MEMORY STICK!!!!!!!!!!

Hello, it's been a year since I bought my Sony 4GB MagicGate Pro Duo memory stick and for a few months now, my PSP has not been reading my memory card. It keeps blinking nonstop and when I try to format it, it says no memory stick inserted. When I play my UMD, it says impossible to access the memory stick. When I download SensMe Channel, it says impossible to access the memory stick and the same for downloading digital comics. SO I TESTED WITH ANOTHER MEMORY STICK AND IT WORKS FINE, PLEASE HELP ME!!!!!!!!!!!!!!!

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