See if the problem is with the memory stick by:
a) removing the stick and see if the camera gets stuck on any pics remaining in the internal memory.
b) trying the stick in a laptop with a Sony stick slot or buy a card adapter that includes the Sony stick -- see if the pics can be read by the computer.
If (a) the camera can't read stuff in the internal memory take camera back to retailer.
If (b) can't read pics on a computer, put stick back in camera and look under Settings for an option to format memory stick -- this will wipe your pictures so first copy the working ones to computer.