...I have a 128MB memorystick which I swap between my Clie PDA, VAIO computer, and occasionally into my television to view pix...it is used pretty hardcore, and has not failed...these CF cards, memorysticks, and SmartMedia cards are very robust and can take quite a beating...are you attempting to format it using your camera, or your computer (assuming you have a MS drive)? I believe most memorystick from Sandisk, Sony, etc. all have a lifetime warranty...if it is Sony, you could run down to the Sony Store and see if they will replace it for free...