Camera Pics Have Shrunk

[Macnick]

I recently took a number of pictures on my digital camera, Olympus Stylus 720SW all at the usual size of 2048 x 1536.

When I put the sim into the card reader they all shrunk to 160 x 120 and are now all reading the same on the camera too, also the computer won't accept them.

Any ideas, could it be a virus or something, really important pics so need to get them back

Thanks