My camera erased my pictures
These cameras have an internal store and also can use a card. So, when you add a card, it is writing to that store and only shows you the pictures stored there unless you change the device settings or remove the card.
If so, the images you have on the EasyShare One internal store may be originals
Another possibility is that you did a BragBook synch to EasyShare and you might be able to see these images in your 'Favorites' view. The 'Camera Favorites' or BragBook pictures are a smaller version of original images, to allow you to carry more pictures with you to share, but these pictures may be a lower resolution version of the images you took. They would be sufficient for printing 4x6 pictures, but not enlargements.
Change to Favorites mode to see if they show up that way.