I took a whole bunch of pictures and several videos on my Samsung S630 camera with a 512 MB memory card in it. Using the camera, I can easily review the pictures and play the movies back on the camera veiw screen. When I try to copy the files onto the computer, they copy over, but I can not view any picture and the videos do not play. I have used this camera for a while, and have not had this problem before. I used it this morning and copied the files over using a 6 in one USB card reader and all the files were fine and readable. I added more to it this afternoon (I did change batteries in-between) and none of the pictures or videos I took this afternoon are viewable on the computer. All can still be viewed in the camera. However, all the files shot earlier in the day were still fine. I can not even view the pictures of videos directly from the memory card while ion the reader. If they play fine on the camera, the files MUST be OK. There is nothing wrong with the card reader or computer as I am able to transfer the files from earlier today with no problem and view them on the computer.